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^/t 2 Nortfc C *°<™ Sftfe library 

°' C Raleigh 



NORTH CAROLINA 
DEPARTMENT OF CONSERVATION AND DEVELOPMENT 

R. BRUCE ETHERIDGE, DiRECTQR 



DIVISION OF MINERAL RESOURCES 

JASPER L. STUCKEY, STATE GEOLOGIST 



Bulletin No. 42 



Chromite Deposits of 
North Carolina 

By 

Charles e. hunter, Thomas g. Murdock 

and 

Gerald r. Maccarthy 



Prifared and Published ih Cooperation with the Tennessee Valley Authority 

under the direction of 
Jasper L. Stuckey, North Carolina Department of Conservation and Development 

and 
H. S. Rankin, Tennessee Valley Authorjty 

• 

RALEIGH 
1942 



Digitized by the Internet Archive 

in 2013 



i 



http://archive.org/details/chromitedeposits1942nort 



North Carolina State library 
Raleigh 

North Carolina 
Department of Conservation and Development 

R. Bruce Etheridge, Director (J, 



Division of Mineral Resources 

Jasper L. Stuckey, State Geologist 



Bulletin No. 42 



Chromite Deposits of North Carolina 

Geology and Mining 
Charles E. Hunter and Thomas G. Murdock 

Geophysics 
Gerald R. MacCarthy 



Prepared and Published in Cooperation with the Tennessee Valley Authority 

Under the Direction of 
Jasper L. Stuckey, North Carolina Department of Conservation and Development 

and 
H. S. Rankin, Tennessee Valley Authority 



Raleigh 
1942 



i 



MEMBERS OF THE BOARD OF CONSERVATION AND 
DEVELOPMENT 

Governor J. Melville Broughton, Chairman Raleigh 

Santford Martin, Vice-Chairman Winston-Salem 

Harry Bailey Spruce Pine 

Oscar Breece Fayetteville 

J. Wilbur Bunn Raleigh 

Bruce Cameron . Wilmington 

K. Clyde Council Wananish 

W. J. Damtoft Asheville 

J. Horton Doughton . Statesville 

Irving F. Hall . Raleigh 

Roy Hampton Plymouth 

J. L. HORNE, Jr Rocky Mount 

William Carl Hudson Morganton 

Charles H. Jenkins Aulander 

Carroll P. Rogers Tryon 

Richard Tufts Pinehurst 

R. Bruce Etheridge, Director 



11 



CONTENTS 

Page 

Letter of Transmittal v 

Preface vi 

Summary 1 

Introduction 2 

Geology 4 

General Geology 4 

Chromite Mineralogy 4 

Description of Chromite Deposits 5 

Buncombe County 5 

Democrat and Morgan Hill Chromite Prospects 5 

Placer-Residual Chromite 5 

Massive and Disseminated Chromite 6 

Vein and Disseminated Chromite 7 

Leicester Chromite Prospect 7 

Madison County 7 

Holcombe Branch Chromite Prospects 7 

Yancey County 8 

Day Book Chromite Prospect 8 

Price Creek Chromite Prospect 9 

Jackson County 9 

Webster Chromite Prospects 9 

Lenses of Massive Chromite 10 

Placer and Residual Chromite 11 

Disseminated Chromite 12 

Addie Chromite Prospect 12 

Chestnut Gap Chromite Prospect 14 

Dark Ridge Chromite Prospect 14 

Macon County . 15 

Corundum Hill Chromite Prospect 15 

Ellijay Chromite Prospect 16 

Norton Chromite Prospect 16 

Iredell County 16 

Plyler Chromite Prospect 16 

Other Chromite Localities , 17 

Magnetic Geophysical Survey of Webster and Democrat Chromite 

Areas 18 

Introduction 18 

Geophysics 18 

Magnetic Methods 18 

Procedure 21 

Webster Area 22 

Magnetic Survey 22 

Interpretation of Results 23 

Recommendations 24 

iii 



CONTENTS— CONTINUED 

Page 

Democrat Area 24 

North Democrat Area 25 

Magnetic Survey 25 

Interpretations and Recommendations 25 

South Democrat Area 26 

Magnetic Survey ' 26 

Interpretations and Recommendations 26 

General Conclusions 26 

Core Drilling of Webster Chromite Prospect 26 

Logs of Core Drill Holes 29 

Mining of Chromite 32 

Problems of Chromite Mining 32 

Placer Operations at Democrat 33 

Recovery of Disseminated Chromite 35 

ILLUSTRATIONS 

Plate Facing Page 

1 Map of Principal Chromite Deposits, North Carolina 2 

2 Map of Democrat and Holcombe Branch Chromite Deposits 6 

3 Map of Day Book Chromite Prospect 8 

4 Map of Price Creek and Norton Chromite Prospects 

5 Map of Webster Chromite Prospect 10 

6 Map of Addie and Chestnut Gap Chromite Prospects 12 

7 Map of Dark Ridge Chromite Prospect 14 

8 Map of Corundum Hill and Ellijay Chromite Prospects 16 

9 Geologic Map of Area Investigated at Webster with Magnetometer 22 

10 Isogamic Map of Northwest Part of Webster Area 

11 Isogamic Map of Southeast Part of Webster Area 

12 Isogamic Map of Northeast Part of Webster Area 

13 Magnetic Relief Model, Northwest Part of Webster Area 

14 Magnetic Relief Model, Northwest Part of Webster Area 

15 Magnetic Relief Model, Southeast Part of Webster Area 

16 Geological Map of Area Investigated at Democrat 24 

17 Isogamic Map of North Part of Democrat Area 26 

18 Magnetic Relief Model, North Part Democrat Area 

19 Isogamic Map of South Part Democrat Area 

20 Magnetic Relief Model, South Democrat Area 

21 Location of Diamond Drill Holes 27 

22 Flow Sheet of Chromite Recovery Plant 36 

23 Fig. A— Small Chromite Vein 

Fig. B — Small Chromite Lens in Dunite 37 

24 Fig. A — Field Magnetometer Party in Action 

Fig. B — Core Drilling for Chromite, Webster, N. C 38 

25 Fig. A — Hydraulicking Placer Chromite, Democrat, N. C. 

Fig. B — Portable Plant Recovering Placer Chromite, Democrat .... 39 

iv 



LETTER OF TRANSMITTAL 

Raleigh, North Carolina 
October 7, 1942 

To His Excellency, Hon. J. Melville Broughton, 
Governor of North Carolina. 

Sir: 

I have the honor to submit herewith, as Bulletin No. 42, a 
report on chromite deposits of North Carolina. 

Chromite is classed as a strategic metal and is needed in 
larger quantities for war use. This report, it is hoped, will point 
out opportunities for the production of chromite in North Caro- 
lina which will lead to its production on a scale which will be a 
contribution to this country's war efforts. 

Respectfully submitted, 

R. Bruce Etheridge, 
Director. 



PREFACE 

Chromite has been known to occur in North Carolina for many 
years and has been referred to briefly in the literature from time 
to time, but the present report entitled "Chromite Deposits of 
North Carolina" is the first attempt to bring together in one 
publication detailed information on chromite deposits of the 
State. 

The investigation has been conducted in cooperation with the 
Tennessee Valley Authority in an effort to furnish information 
that may lead to an increased production of chromite in the 
present emergency. In addition to geological examinations, some 
of the more promising areas were investigated by geophysical 
methods. While no large bodies of ore were discovered, it is 
hoped the information contained in the report may be of value 
to those interested in the chromite deposits of North Carolina. 

Jasper L. Stuckey, 
State Geologist. 



VI 



CHROMITE DEPOSITS OF NORTH CAROLINA 

SUMMARY 

Since 1870 chromite has been known to occur in western North Carolina in, and 
closely associated with, the dunite (olivine) deposits of the area. All the chromite de- 
posits are small, usually only a few hundred tons in each deposit. Most of the chromite 
is rather low grade, that is, the chromium oxide content is less than 45 per cent and the 
chromium-iron ratio is less than 2.5 to 1. However, there are a few occurrences where 
the chromite when concentrated is high grade with a Cr^0 3 content greater than 48 per 
cent. The two principal occurrences of high grade ore suitable for beneficiation are the 
Day Book, (Yancey County), mainly a vein deposit, and the Democrat, (Buncombe 
County), mainly a placer-residual deposit. 

For over 50 years there has been sporadic production, mainly during war times, of 
chromite from the North Carolina deposits, the total probably being less than 1000 tons. 
The future production will also be intermittent with the main production during abnormal 
times. These North Carolina deposits are best suited to remain as reserves for limited 
production during times of national emergency. 

Careful geological investigation of all the known occurrences of chromite in the area 
indicated that the formations at Webster and Democrat offered the best chances for con- 
taining concealed ore bodies of commercial size and small selected areas were surveyed by 
magnetic geophysical methods. Although these surveys did not show any outstanding 
magnetic features that indicated the existence of large chromite bodies, they did find 
several small magnetic "lows" which indicated the probable existence of some small lenses. 
To prove more definitely the presence or absence of chromite under the magnetic "lows", 
three of these "lows" were tested by six core drill holes. 

The core drilling results were not very encouraging as no chromite bodies were en- 
countered of sufficient size to be commercially developed under normal conditions. How- 
ever, all six holes intersected some chromite, mainly disseminated material of about 3 per 
cent chromite. Apparently the magnetic "lows" were caused by the presence of under- 
lying lean disseminated chromite. One of the drill holes at a depth of 97 feet intersected 
a two-foot zone of vein chromite which apparently is the continuation of the same vein 
showing on the surface almost directly over the point of intersection. 

The magnetic survey and core drilling proved that there is insufficient difference in 
magnetic properties between the chromite and enclosing dunite mass to outline ac- 
curately the ore body by standard magnetic geophysical methods. In addition, the core 
drilling showed that the North Carolina chromite ore bodies are small disconnected lenses 
with much lean or barren area between. 

If the shortage of chromite should become sufficiently acute to justify the high cost 
of chromite production from the North Carolina deposits, the following occurrences merit 
consideration : 

1. The residual-placer chromite at Democrat, Webster, and Corundum Hill. 



2 Chromite Deposits of North Carolina 

2. Vein and lens chromite at Day Book and Dark Ridge. 

3. Disseminated and lens chromite at Webster. 

It is estimated that each of these prospects can furnish several hundred tons of 
chemical grade (plus 45 per cent Cr 2 3 ) chromite per year, and there are several other 
smaller occurrences from which a few tons could be recovered. 1 



PLATE I 



PRINCIPAL 

WESTERN 


CHROMITE DEPOSITS 

or 
NORTH CAROLINA 

SCALE r ~J 


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N C M B It 

B _/MC DOWELL '. 

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• LOCATION OF CHROMITE DEPOSIT ,^*""s^ 

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INTRODUCTION 

The principal occurrences of chromite in western North Carolina are limited to a few 
localities in Buncombe, Jackson, Macon, Madison, and Yancey Counties. The most impor- 
tant deposits in these counties are the Day Book, Yancey County; Democrat, Buncombe 
County ; and Dark Ridge and Webster, Jackson County. During abnormal economic con- 
ditions or when chromite value was over $50 per ton, small tonnages of chromite were 
produced from these and other smaller deposits, usually less than 200 tons from each dur- 
ing the period. All of these deposits are accessible by good all-weather roads and the 
Webster and Dark Ridge occurrences are on or near the railroad. 

The purpose of this survey was to locate the North Carolina chromite deposits, ap- 
praise their economic aspect, and make available information regarding these deposits so 
that the best of them could be put into immediate production if war conditions become 
such that production from these deposits is essential to the national security. Magnetic 
geophysics had not been used in locating chromite ore bodies in the Southern Appa- 



1. Eckel, E. C, and Hunter, C. E., "Iron, Chromite, and Nickel Resources of the Tennessee Valley Region," 
TVA Geologic Bulletin No. 10, (1938) p. 20. 



Chromite Deposits of North Carolina 



lachians ; therefore, this method of prospecting was included to determine its value in this 
area. The magnetic survey was followed by core drilling to check the magnetic results 
and to determine the practicability of blocking out North Carolina chromite ore by core 
drilling. 

The field work was done as a cooperative project between the Division of Mineral Re- 
sources of the North Carolina Department of Conservation and Development and the 
Regional Products Research Division of the Commerce Department, Tennessee Valley 
Authority, and extended from June 17, 1941, to September 16, 1941. The survey was 
under the general supervision of Dr. Jasper L. Stuckey, State Geologist of North Caro- 
lina and Mr. H. S. Rankin, Senior Mining Engineer, Tennessee Valley Authority. Mr. 
Charles E. Hunter, Associate Geologist, Tennessee Valley Authority, and Mr. T. G. 
Murdock, Assistant State Geologist, North Carolina, were in charge of the field operation. 
Dr. Gerald R. MacCarthy, Professor of Geophysics and Geology, University of North Caro- 
lina, conducted the magnetic geophysical survey. Five student aides, Mason K. Banks, 
John W. Harrington, R. S. Ingle, Roy L. Ingram, and William T. McDaniel, Jr., were em- 
ployed in conducting the survey. 

The authors acknowledge with appreciation the kindly assistance of many local 
residents of western North Carolina, and especially that of Mr. Julius H. Gillis, of Olivine 
Products Cpn., Webster, and Mr. Marshall Gravatt, of Southern Mineral Cpn., Democrat. 



ECONOMICS AND USES OF CHROMITE 

The War Department as early as 1917 placed chromite high on the list of strategic 
minerals because of its limited domestic occurrence and its essential use in the production 
of armaments. It is necessary to depend almost entirely on imports. Chromite (FeCr 2 4 ) 
is the only commercial mineral used as an ore of chromium and is converted in an electric 
furnace to ferro-chromium before it is added to the steel bath to make alloys and stain- 
less steel. Chromium plating is used in the cutting tool industry to produce a hard durable 
surface, and chromite brick and ground chromite are used as neutral refractories in fur- 
nace construction. Chemical industries use chromium salts in electroplating, dyeing, tan- 
ning, pickling nonferrous metals, and making pigments. 

In the United States 50 per cent of the consumption of chromite is for metallurgical 
purposes, 40 per cent for refractory purposes, and 10 per cent for chemical and other 
purposes. 1 

Between the years 1925 and 1940 the average domestic price was about $20 per ton. 
Since the latter date the market price has continued to increase, and during the first 
quarter of 1942 it exceeded $40 per long ton of 48 per cent Ci\.0 :4 (with a Cr:Fe ratio of 
2.5:1) f.o.b. mines. During 1917-1918 the price went above $70.00 per ton. 



1. Seil, G. E., Chromite (Chapter): Am. Inst. Min. and Met. Eng., Intl. Mineral and Rocks, New York, 
1937, p. 199. 



4 Chromite Deposits of North Carolina 

GEOLOGY 

General Geology 

The occurrence of chromite in North Carolina is restricted almost entirely to the 
mountainous western part of the State. Chromite in quantities greater than a trace is 
found associated only with peridotite rocks, mainly of the olivine variety, which are in- 
trusives into crystalline gneisses and schists of Pre-Cambrian age. These metamorphics 
have also been intruded by younger granites and pegmatites ranging in age from Pre- 
Cambrian to Carboniferous. In these Pre-Cambrian formations the prevailing foliation 
is northeast-southwest and commonly dips toward the southeast, but there are consider- 
able local variations in both strike and dip, and in some places the rocks are contorted in 
a complicated manner. 

The olivine formations are usually less than a mile in length, although some extend 
for several miles, and the width is generally about one-fourth to one-third of the length. 
These olivine chromite-bearing formations usually occur with hornblende gneiss, 1 but may 
also occur with the micaceous gneiss and schist. 2 The chromite occurs in the olivine for- 
mations as disseminated crystals in an olivine matrix, disconnected small lenses, narrow 
veins, or as relatively large crystals in talc veins. In addition to this primary chromite, 
there are residual and placer deposits that have been weathered free from the olivine for- 
mation. It is only with the residual and placer deposits that tonnage estimates of reserves 
can be made. The primary chromite in the dunite is so irregular in occurrence and extent 
that estimates cannot be made and only the ore in sight can be considered as reserve. 

The geology of these olivine formations is described in more detail in the publications 
"Corundum and the Peridotites of Western North Carolina 15 and Forsterite Olivine De- 
posits of North Carolina and Georgia", both by the North Carolina Geological Survey 4 . 

Mineralogy of Chromite 

Chromite is iron-black to brownish-black in color; with hardness of 5.5; specific 
gravity, 4 to 4.6 ; luster submetallic to metallic and sometimes feebly magnetic. It varies 
greatly in composition as it is an isomorphic mixture. The chromium atom is replaceable 
by several other isomorphic elements. This relationship has been described by J. Volney 
Lewis, 5 as follows : 

Variations in color, luster, and degree of translucence are comprehensible in 
view of the chemical character of chromite. Its composition is commonly repre- 
sented by the formula FeCr^Oj, or FeO, Cr-0 3 , which corresponds to 67.86 per 
cent chromic oxide (Cr 2 3 ) . Few analyses, however, show even as much as 60 per 
cent Cr^Os, and they range from this down to 35 per cent and lower. 

This wide variation, which is obviously of the greatest practical importance, 
arises from the fact that chromite is a member of an isomorphous group of min- 



J. Roan Gneiss. Arthur Keith, "Mount Mitchell Folio, North Carolina-Tennessee," Geological Atlas of 
U. S. No. 124, 1905). 

2. Carolina Gneiss. Arthur Keith, op. cit. 

3. Pratt, J. H., and Lewis, J. V., "Corundum and Peridotites of Western North Carolina," N. C. Geol. and 
Economic Survey, Vol. 1, 1905. 

4. Hunter, C. E., "Forsterite Olivine Deposits of North Carolina and Georgia." N. C. Dept. Cons, and 
Devel. Bull. 41, 1941. 

5. Lewis, J. V., "Chrome-Ore Deposits in North Carolina," Engineering and Mining Journal, Vol. 109, No. 
20, M. 1920, pp. 1112-1114. 



Chromite Deposits of North Carolina 



erals which are capable of mingling in all proportions to form homogeneous 
"mixed crystals". In other words, the crystals and grains of such a mineral may 
show its own characteristic constituents to be replaced in varying degree by the 
corresponding elements of other members of the group. The spinel group, as it is 
called, includes spinel, MgAl 2 4 ; hercynite, FeAl 2 4 ; magnetite, FeFe 2 4 ; 
(mitchellite) ; and a number of other related aluminates. Hence chromite, when 
it is crystallizing, may have a part of its ferrous iron replaced by magnesium, 
which is an abundant constituent of the peridotites ; and in a similar manner 
aluminum and ferric iron, when present, may be substituted for a part of the 
chromium. The latter process reduces the chromium content, and therefore yields 
a mineral of less value ; the former makes a desirable reduction in the percentage 
of iron. The result is equivalent to mixing the molecules of the four minerals 
named above, and hence the composition of chromite in general may be repre- 
sented by the formula (Fe, Mg) (Cr, Al, Fe) 2 4 . 

It follows that the limit to the possibility of improving the grade of a chrome 
ore by concentration is always lower, and may be far lower than that set by the 
theoretical chromite molecule, FeCr 2 4 . For any particular locality or deposit 
that limit can be determined only by chemical analyses of sufficient number and 
accuracy to establish the average composition of the essential ore-mineral, 
chromite. 

In addition to the variations in the composition, some of the primary chromite has 
been partly altered to chlorite. The chromite is rather difficult to free from the gangue 
minerals, olivine, serpentine, talc, chlorite, and various secondary minerals. At Webster, 
kammererite, a peach-blossom colored chromium-bearing chlorite, is found associated with 
almost all of the chromite. 

DESCRIPTION OF CHROMITE DEPOSITS 

For convenience of description of deposits, the occurrences are taken up by counties. 
The deposits have been named after prominent geographic points at, or near, the deposit 
and in most cases these names coincide with the names applied to these deposits in pre- 
vious reports. No attempt has been made to make chromite tonnage-reserve estimates 
because of the irregular nature of these deposits, which is discussed elsewhere in this 
report. 

BUNCOMBE COUNTY 

Democrat and Morgan hill Chromite prospects 

Chromite occurs with a dunite formation about 3000 feet west of Democrat, Bun- 
combe County, the main part occurring between Ivy Park Church and Ivy River (see 
Plate 2). The chromite occurs as placer-residual deposits, small massive veins and lenses, 
and disseminated crystals in dunite. 

placer-residual Chromite 

Placer chromite mixed with clays and gravels occurs along a small drain on the west 
contact of the formation. This placer area is about 1200 feet long and averages 100 feet 
wide. It is not very thick, averaging less than eight feet to bedrock. 



Chromite Deposits of North Carolina 



This placer area was partly worked during 1917-1918 at which time the chromite was 
recovered by washing and tabling. It is reported that the chromite recovered contained at 
least 48 per cent Cr-.0 3 . The chromite occurring in this placer consists almost entirely of 
small (V8 inch or less) octahedral crystals making up about four per cent of the placer. 

On the northeastern slope of the dunite formation towards Ivy River and Democrat 
there is residual and placer chromite. This area consists of about three acres and is under- 
lain by clay, gravel, and placer material averaging approximately five feet in thickness. 
During the summer of 1941 part of this placer area was worked for chromite. The ma- 
terial was recovered by a hydraulic process described elsewhere in this report. The placer 
is reported to contain five or six per cent chromite, most of which is apparently recover- 
able. The chromite liberated from the weathering of dunite consists mainly of octahedral 
crystals and small fragments of massive chromite. The following is a chemical analysis 1 
of the chromite recovered by the portable plant: 



Cr 2 3 


Fe 2 3 


Si 


P 


S 


Cr:Fe 


55.52 


28.50 


0.80 


0.07 


Trace 


1.9:1 



There is an area underlain by residual chromite near the southwestern end of the 
Democrat dunite formation. This material is principally on the southeast side of the high- 
way N. C. No. 695 about 1500 feet southeast of Morgan Hill Church. There are about six 
acres underlain by the residual-placer chromite, principally in clay, averaging about five 
feet deep. This placer was drilled and sampled a short time ago and it is reported to con- 
tain about three and one-half per cent Cr 2 3 . 

MASSIVE AND DISSEMINATED CHROMITE 

In the Democrat dunite formation there are several small lenses of massive and vein 
chromite. Small pits have been made on showings of massive and vein material at a point 
a few hundred feet southwest of the McKinney family cemetery. This location is also a 
few hundred feet south of a feldspar mine on the south side of Ivy River west of Demo- 
crat. One of these pits is 6 by 12 feet and 6 feet deep. Disseminated chromite shows in 
the walls of the pits, and parallels the major joint system of the dunite which is N 25° E. 
It is reported that about five tons of massive chromite was removed from this pit, of 
which one ton remains beside the pit and contains about 80 per cent chromite. The frac- 
tures are filled with talc, kammererite, and nickel silicate minerals which were formed in 
fracture planes some time after the chromite. 

A small pit occurs about 50 feet northeast of the one just described. This pit appears 
to have encountered about one-half ton of vein chromite. Material on the dump indicates 
that the vein was about six inches wide. 

A zone of rather rich disseminated chromite occurs a few hundred feet northeast of 
the feldspar mine. This location is 300 feet northwest of Ivy River. During 1917-1918 
a shaft was made in this disseminated ore to a depth of about 50 feet and is reported to 
have cut through a zone of rich disseminated chromite ore about three and one-half feet 



1. Analysis by J. W. H. Aldred, Research and Development Division, Tennessee Valley Authority, Wilson 
Dam, Alabama. 



PLATE 2 




Chromite Deposits of North Carolina 



wide. The disseminated zone strikes northeast and southwest and dips to the southeast. 
The disseminated ore consists of thickly spaced crystals in an olivine matrix with the 
chromite making up as much as 75 per cent of the material. An analysis of the chromite, 
including the olivine matrix, contains 29.5 per cent Cr^.Cv 1 

About 100 feet to the southeast of this shallow shaft there is an exposure of similar 
disseminated chromite which shows at several points, varying from a few inches to three 
feet in width. The extent of this disseminated ore is not known. 

All of these disseminated zones of ore are probably along a fracture system in the 
dunite. The richer part of the ore is thought to occur as irregular lenses. 

VEIN AND DISSEMINATED CHROMITE 

Vein and disseminated chromite occurs in the dunite at a point about 1100 feet north- 
east of Morgan Hill Church and a few feet east of the highway, N. C. No. 197 (see Plate 
2). A cut has been made along the exposure which is about 25 feet east of the west con- 
tact of the dunite formation ; it is 50 feet long, 12 feet wide, and averages 15 feet deep. All 
the olivine exposed in the cut is fine-grained and a light yellowish green in color. Most of 
this olivine contains disseminated chromite which is fine-grained but crystals range in size 
up to 14 inch in diameter. 

In the southern part of the pit the disseminated chromite zone is about 4 feet wide 
and probably contains about 60 per cent chromite. In the extreme southern end of the 
pit, the chromite zone has narrowed to a width of about 18 inches. In the northern end of 
the cut only a small amount of chromite is exposed. However, the cut appears to have 
been driven too far to the west and, therefore, away from the disseminated chromite zone. 

At the center of the cut is a shaft 10 by 10 feet which has been sunk to a depth of 
about 75 feet. This shaft is timbered and full of water. The material on the dump indi- 
cates that the shaft encountered rich disseminated and vein chromite of a rather black 
color but shows minor alterations to kammererite in places. It is not known how much 
chromite was removed from this shaft but probably less than 10 tons. 

Leicester Chromite Prospect 

State Highway No. 63 crosses a dunite formation one-fourth mile east of Leicester, 
Buncombe County. This dunite is highly serpentinized and weathered, and contains a 
small amount of disseminated chromite in the form of octahedral crystals. Where the 
dunite has weathered, these crystals have accumulated in the residual material in a suffi- 
cient amount to be considered a possible source of chromite. The dunite underlies about 
six acres. 

MADISON COUNTY 

HOLCOMBE BRANCH CHROMITE PROSPECTS 

Chromite occurs on Holcombe Branch 1200 feet north of Pleasant Gap and one and 
one-fourth miles southeast of Beech Glen, Madison County, and is associated with the 
Holcombe Branch dunite formation (see Plate 2). Parts of the dunite rock contain about 



1. Analysis by Tennessee Valley Authority Minerals Testing Laboratory, Norris, Tennessee. 



Chromite Deposits of North Carolina 



two per cent disseminated chromite crystals, which are usually associated with sound 
olivine. The disseminated chromite is most noticeable in the road cut along the north 
side of the branch. 

• 
There is placer chromite along Holcombe Branch across the dunite formation and 

downstream for several hundred feet below the contact of the formation. This placer 
material extends on each side of the branch for about 75 feet and appears to have an aver- 
age thickness of about 4 feet. Pieces of chromite 4 inches in diameter are rather numer- 
ous in the placer material but the remainder is mainly coarse rock. The chromite-bearing 
zone extends along the creek for a distance of about 1,000 feet. 

Vein chromite associated with corundum occurs in the northeast part of the Holcombe 
Branch dunite. This occurrence, a short distance west of the east contact, is north of the 
branch and about 3,000 feet northeast of Pleasant Gap. The chromite was encountered in 
mining corundum a number of years ago. The corundum shafts are now caved, so the 
actual chromite-corundum veins could not be examined, but the dumps around the shafts 
contain blocks of chromite-corundum, many of which are two and one-half feet or so in 
diameter. The chromite is very black ; the corundum is massive and slightly pink. This 
prospect is worth investigation because of the possibilities of producing chromite and 
corundum from the same operation. 

YANCEY COUNTY 

DAY BOOK CHROMITE PROSPECT 

The Day Book chromite prospect (old Ray Mine) occurs one mile southeast of Day 
Book, Yancey County, (see Plate 3). The chromite is associated with a lens-shaped du- 
nite formation trending northeast-southwest and occurring on both sides of Mine Fork 
Creek. 

Near the crest of the hill on the east side of Mine Fork Creek, there is an abandoned 
shaft in one of the chromite prospects about 50 feet from the northeast contact. This 
deposit was first prospected about 1901 by shallow trenches and pits. During 1917-1918 it 
was again opened up by a shaft 75 feet deep with some drifting near the bottom. At this 
time two carloads of ore were produced. The shaft encountered a vein of chromite which 
was reported to be about 15 inches thick, and numerous tiny veinlets associated with the 
wall rock. It appears that the mining operations as practiced were quite wasteful as only 
the large chunks were shipped and the smaller veinlets were thrown away instead of being 
milled. The chromite found in the old dump is an unusually coarse-grained material and 
occurs directly in contact with extra high-grade, coarse-grained olivine. In addition to 
the chromite and olivine, there is much soapstone and talc on the dump. The chromite in 
the dump is tar black in color on a fresh surface and coarsely crystalline, the crystals be- 
ing distorted and elongated by squeezing and fracturing. 

A chipped sample of the chromite including some matrix from the dump has the fol- 
lowing analysis: 1 

Cr 2 3 Fe 2 3 Si0 2 Al 2 8 MgO Total Cr:Fe 

44.20 20.05 0.30 21.30 14.48 100.33 2.14:1 



1. Chemical analysis by W. A. Reicl, Division of Mineral Resources, North Carolina Department of Con- 
servation and Development, Raleigh, N. C. 



PLATE 3 





Br£ 



fl& 



<K\V Clermont Ch 



Day Book 



e V- \ ^V\ Peterson Chapel 



yZion Ch 





// 






x 



x 

DAY BOOK 
CHROMITE PROSPECTS 



Mine 

fork School 



Scale 1000 




-F=t- 




1000 

i — 



2000 Feet 



I I I 



DRWN 

trcdZ£W.-. 

CHKD 



DATE MADE CHKD SUPV. INSP, 



COMPUTED 



CHROMITE SURVEY, YANCEY CO., N.C. 



GEOLOGICAL INVESTIGATION 

OF 

DAY BOOK CHROMITE PROSPECT 



N C DEPT OF CONSERVATION AND DEVELOPMENT 

DIVISION OF MINERAL RESOURCES 

AND 

TENNESSEE VALLEY AUTHORITY 

COMMERCE DEPARTMENT 



KNOXVILLE 



4-16-42 W CO I 82IGI2R0 



NORTON CHROMITE PROSPECT 



PLATE 4 



X 
X 




NORTON CHROMITE 
PROSPECT 

Creek 



NORTH CAROLINA 



MACON 



GEORGIA 



CO 




4/ 



PRICE CREEK CHROMITE PROSPECT 




PRICE CREEK 
CHROMITE PROSPECT 



^ Democrat "10 




Scale 1000 



2000 Feet 



CHROMITE SURVEY 

MACON AND YANCEY COUNTIES, N.C. 



GEOLOGICAL INVESTIGATION 

NORTON AND PRICE CREEK 

CHROMITE PROSPECTS 



N.C. DEPT OF CONSERVATION AND DEVELOPMENT 

DIVISION OF MINERAL RESOURCES 

AND 

TENNESSEE VALLEY AUTHORITY 

COMMERCE DEPARTMENT 



KNOXVILLE 



4-16-42 W CO I 82IGI I FK 



Chromite Deposits of North Carolina 



During 1917-1918 some prospecting by pits was carried out on the southwest end of 
the formation where some chromite was found similar to that on the other end. However, 
the prospecting probably uncovered less than ten tons of chromite, most of which is very 
black. It occurs as small pockets, most of which are vein-like segregations in fresh gran- 
ular olivine. More prospecting at this point should reveal similar pockets of chromite. 
There are possibilities that a small tonnage of chromite could be recovered from the soil 
along the northern part of the dunite formation. The Day Book prospect is worthy of 
further development work. 

PRICE CREEK CHROMITE PROSPECT 

The Price Creek chromite prospect is located in Yancey County about one mile north- 
east of Price Creek school (see Plate 4). This occurrence is up the second branch on the 
north side of Blankenship Creek. The prospect consists of several pits on the east side of 
a hill about 100 feet above the creek. A small amount of chromite was mined here about 
50 years ago. Around these pits and on their dumps there is relatively sound granular 
olivine. Chromite occurs in the dump material as small veins and large one-half inch blebs. 

Pratt and Lewis 1 mention this prospect and state that a pocket of chromite yielded 
seven tons of ore and was then exhausted. An assay by Baskerville 2 gave a content, for 
a selected sample, of 59.20 per cent Cr 2 3 and 25.02 per cent FeO. 

The dunite formation at Price Creek is largely concealed by overburden. There may 
be other small pockets of high grade chromite concealed by this overburden. 

JACKSON COUNTY 

Webster Chromite Prospects 

The town of Webster, Jackson County, is located on the western part of the Webster- 
Addie dunite ring dike. :i There are a number of chromite prospects within a distance of 
one and one-half miles of Webster, most of which have been intermittent producers of 
chromite for short periods of time during the last fifty years. This small production has 
coincided with times when chromite was selling for abnormally high prices, such as the 
war period of 1917-1918. The tonnage and grade of the ore produced is not known, but the 
total is believed to have been less than 600 tons of merchantable ore. 

The occurrence of chromite at Webster (see Plate 5) is of three types: (1) small 
lenses or pockets of massive or semi-massive chromite in fault zones or in the contact of 
the formation ; (2) placer, or residual, material derived from weathered dunite ; and (3) 
thickly spaced disseminated chromite crystals and small veins in relatively sound dunite. 
The chromite production at Webster has been from the massive lenses or the weathered 
disseminated material. 



1. Pratt, J. H., and Lewis, J. V., "Corundum and Perldotites of Western North Carolina," Vol. 1, N. C. 
Geological Survey, p. 382. 

2. Ibid. 

3. Hunter, C. E., "Forsterite Olivine Deposits of North Carolina and Georgia," N. C. Dept. Conservation 
and Devel. Bull. No. 41, (1941) p. 82. 



10 Chromite Deposits of North Carolina 



LENSES OF MASSIVE CHROMITE 

Float chromite of the massive very black type occurs in a field and along the small 
creek north of the town of Webster. The largest chromite float occurs ajong the east side 
of the creek at a point about 1,800 feet due north of the Webster Post Office and 1,000 feet 
south of the cemetery. In the field a few hundred feet east of the creek, pieces of massive 
chromite six inches in diameter are not uncommon. Some of these pieces appear to be 
clusters of crystals one-half inch or more in diameter which have had the crystal corners 
dissolved or replaced by chlorite. The source of this float chromite has not been determined 
but it is probably from a concealed pocket of chromite near the upper edge of the field. 
This area is worthy of prospecting. 

A lens of massive chromite similar to the material described above has been partly 
mined out between the road and Mill Creek at a point about 800 feet southeast of the 
Webster Post Office. The old pits are partly filled because of the caving of the sides. This 
was one of the first deposits worked for chromite in the Webster area and the only one 
worked near the center of the dunite mass. 

Other small lenses of semi-massive chromite occur along the western part of the du- 
nite formation south of the Tuckasegee River. Most of these occurrences are in or near 
the western contact zone and less than one-half mile south of the river. The best of these 
exposures have been opened up by cuts or trenches and part of the past chromite produc- 
tion from Webster has come from these works. The pits and trenches are partly filled from 
caving and have a heavy growth of concealing vegetation. The ore exposed in the work- 
ings, and on the surface beside them, for the most part consists of clusters of rounded 
chromite crystals probably averaging one-fourth inch in diameter and separated by talc 
and chlorite. Even most of the massive chromite observed contains talc in the cracks. 
The ore as a whole has a dull black color and probably is of the high iron ratio variety. 
The size of these small chromite lenses is not known, but they are probably worthy of 
further prospecting. 

A small lens of semi-massive chromite is exposed by a trench about one and one-half 
miles southeast of Webster. The pit is located west of the Tuckasegee River and about 
1,200 feet due west of the mouth of Ash Branch. The pit is near the outside contact of 
the Webster-Addie dunite ring dike, and is a crescent-shaped cut about 100 feet long, 5 
feet wide, and 15 feet deep. Most of the cut parallels the contact of the dunite formation 
but is located about 75 feet in from the contact. The cut encountered altered dunite and 
saxonite with fracture seams filled with nickel silicate minerals. The cut appears to have 
followed a fault along which there are small seams and lenses of chromite. The greatest 
amount of chromite was encountered at the extreme west end of the cut where the chro- 
mite is reported to have been about 3 feet thick at the thickest point exposed. It is re- 
ported that when the pit was abandoned, a chromite vein about 6 inches wide was showing 
in the bottom. 

Probably about 20 tons of chromite was removed from this cut, most of which re- 
mains stocked beside the opening. This chromite consisted of blocky material mixed with 
talc and olivine with the size of these blocks ranging up to 1 x 1 x 2 feet. These angular 
blocks for the most part consist of small veins, clusters of rounded crystals, and thick 
disseminated chromite. The material appears to have been brecciated after it was formed, 



PLATE 5 




Ch no mite Deposits of North Carolina 11 



with the fractures being filled with talc, chlorite, and small chromite crystals. The olivine 
associated with the vein chromite is sound green granular material suggesting a late in- 
trusion. A chipped sample of chromite including the matrix from the material on the 
dump beside the pit has the following analysis: 1 



Cr 2 3 


Fe 2 3 


Si0 2 


Al,0 :i 


MgO 


Total 


Cr:Fe 


22.61 


18.91 


16.90 


16.70 


24.62 


99.74 


1.16:1 



It is logical to assume that similar chromite lenses are concealed along this fault 
zone. Continued prospecting in the immediate area might uncover more chromite. 

PLACER AND RESIDUAL CHROMITE 

In the Webster area there has been no attempt to recover placer chromite, although 
some chromite was washed out of the richest residual material during the last war. Some 
of the small creeks that have their entire drainage source on the dunite formation contain 
enough placer chromite to justify prospecting. 

A small branch enters the Tuckasegee River about 500 feet northwest of the Olivine 
Products Corporation Plant southeast of Webster, and drains an area exclusively under- 
lain by the dunite formation. Since it has a gentle drainage slope over 4,000 feet long, it 
is logical to assume that the chromite weathering out of the dunite rock would accumulate 
along this small drainage way. Samples taken from the bank of this branch and panned 
appear to contain up to 5 per cent chromite, most of which is in fragments less than one- 
eighth of an inch in diameter. 

Another small branch enters the river about 300 feet northeast of the plant, and flows 
along the contact of the formation for part of its course. This branch is also about 4,000 
feet long, but there is placer chromite only on the upper part of this branch over the 
dunite formation and down the branch for several hundred feet below the contact. Near 
the contact, or 2,500 feet from the plant, the placer material consists of small chromite 
fragments mixed with stream-transported gravels. At this point over an area of about 
two acres, pieces of chromite ranging in size from i/o to 10 inches in diameter are notice- 
able on the surface ; the larger pieces consist of clusters of black shiny chromite crystals 
in a talc and chlorite matrix and the smaller pieces consist of crystals and small fragments 
of nearly pure chromite. In places part of the placer gravels and clays are probably at 
least 15 feet thick. 

The upper left fork (northeast) contains placer and residual chromite along the 
branch and on the hill slopes on both sides, in some places more than 25 feet thick. The 
chromite in this area is mostly fine material less than Va inch in diameter and is asso- 
ciated with clay containing chalcedony rock fragments. 

At and near the gap, 2000 feet due west of the mouth of Ash Branch, there is an 
area of probably four or five acres, containing residual chromite. On both sides of this 
gap the dunite formation is weathered to a depth of at least 40 feet. In the gap a core drill 
hole encountered rock at a depth of 91 feet. 



Chemical analysis by W. A. Reid, Chemist, Division of Mineral Resources, N. C. Dept. Conservation 
and Development, Raleigh, N. C. 



12 Chromite Deposits of North Carolina 



DISSEMINATED CHROMITE 

Near the gap 2000 feet due west of the mouth of Ash Branch, there is a zone of lenses 
of disseminated chromite ore. This ore zone occurs from 20 to 50 feet # south of the inside 
contact of the Webster-Addie ring dike and is traceable from surface exposures and show- 
ings in cuts for an east-west distance of about 325 feet but is best exposed in the eastern- 
most cut. At this point the ore is about 3*4 feet wide and contains approximately 35 per 
cent chromite. Near the west end the disseminated zone is probably a little more than 
3 feet wide and, in addition, contains a small amount of vein ore. The disseminated and 
vein chromite has a vertical dip and is associated with altered dunite in which the fracture 
zones are filled with nickel silicate minerals. 

This area of disseminated chromite was worked during 1917-1918 and it is reported 
that four carloads of 45 per cent plus ore were recovered. Two open cuts, less than 100 
feet long and about 25 feet wide, were made on the weathered part of the disseminated 
zone. The depth of the cuts probably did not exceed 25 feet (see Plate 9). It is reported 
that a shaft was sunk on the ore in the bottom of each cut to a depth of about 50 feet 
below the bottom of the cut. Ore was removed from each shaft as is indicated by sound 
dunite, containing disseminated chromite, scattered around the collar of the shafts. It is 
logical to assume that this type of ore would extend down for several hundred feet, prob- 
ably as shoots plunging to the west. The mining activity at these cuts and shafts during 
1918 has been described by Lewis. 1 

This area is the most promising one for the production of any substantial tonnage of 
chromite in the Webster area. The best of the weathered zone has been about worked 
out ; so future production will have to be in the hard rock zone usually encountered about 
50 feet below the surface. 

Addie Chromite prospect 

There are several showings of chromite in the dunite ring-dike in the vicinity of 
Addie, Jackson County, (see Plate 6). The chromite is best exposed in prospect pits 
located less than one-half mile southeast of the Southern Railway Station at Addie, and 
about the same distance east of the Fisher home. 

One of these pits is on the north slope of a rounded hill 1,200 feet southeast of the 
station and the same distance east of the Scott Creek bridge. The pit is now partly filled, 
but it appears to have been about 6 feet deep with a diameter at the top of 5 feet. It is 
reported that about three-fourths of a ton of chromite was taken out. At the present time 
a one-half ton dump is beside the pit. 

The chromite showing in the pit and that removed appear to have come from a small 
lens, probably originally about three feet thick, occurring in a fault zone. The chromite 
removed from the pit is composed almost entirely of fractured rounded blebs of black shiny 
chromite separated by talc, anthophyllite asbestos, and white chlorite. One-tenth of an 
inch is the average diameter of the individual blebs although some of them range up to 
one-half inch in diameter. These blebs seem to have been formed from massive chromite 
which has been crushed and shattered by faulting. The faulted and brecciated chromite 
was later cemented by the associated talc, chlorite, and asbestos. 



1. Lewis, J. V., "Deposits of Chrome Ore in North Carolina." U. S. G. S. Bulletin 725, pp. 125-130. 



KLA I L 



Addie No I 
& Joe Mfn 



Bufr Creek Ch 




WILLITS 



^Scoff 



_BM 2555 



§p/f 



Jugar/oe,. 



ei Career Mtn 




CHESTNUT GAP 
CHROMITE PROSPECT 



Bryson 
School 




Chestnui Gap 



Scale 1000 



1000 

— --- 



2000 Feet 



1 I I I 



1 I I I 



REV. 
NO. 



DATE MADE CHKD SUPV. INSP, 



DRWN. 

TRCD.££A,_ 

Lhkd 



COMPUTED 




CHROMITE SURVEY JACKSON CO.. NX. 



GEOLOGICAL INVESTIGATION 

OF ADDIE AND CHESTNUT GAP 

CHROMITE PROSPECTS 



N C OEPT OF CONSERVATION AND DEVELOPMENT 

DIVISION OF MINERAL RESOURCES 

AND 

TENNESSEE VALLEY AUTHORITY 

COMMERCE DEPARTMENT 



KNOXVILLE 



4-15-42 W CO 



82IG20ro 



Chkomite Deposits of North Carolina 13 



The weak shattered zone in which the chromite occurs is a part of a 20-foot fractured 
area striking N 47° E and dipping 48° SE. There are several small showings of chromite 
within the shattered area, and associated with it is sound green granular olivine. 

Chromite float can be found along the strike of the fractured zone both to the north- 
east and southwest of the pit for several hundred feet. The float is the same type ma- 
terial as that exposed at the pit. It it doubtful that there is enough chromite in this 
shattered zone to economically mine under normal conditions. 

A chipped sample of chromite from the pit has the following analysis: 1 



Cr 2 0, 


Fe 2 3 


SiO-2 


Al 2 3 


MgO 


Total 


Cr:Fe 


29.46 


19.89 


11.40 


24.00 


15.74 


100.49 


1.45:1 



A small pocket of chromite was uncovered a few years ago in the outside curve of the 
road at a point 1,200 feet southeast of the station. The point at which the chromite was 
found is near where a small drain crosses the road. This location is southwest and along 
the strike of the fractured zone previously described, and therefore the occurrence is prob- 
ably similar. It is reported that about 300 pounds of chromite was taken out of this 
location. 

Float chromite is found on the crest of a narrow ridge at a point about 1,700 feet south 
of the station. This location also appears to be in the fractured zone cutting across the 
dunite formation in a northeast-southwest direction. The center of the float area is about 
175 feet east of the west contact. The chromite has long been exposed to the weather but 
it has a similar appearance to that occurring at the pit on the round hill to the northeast, 
previously described. 

Disseminated chromite in sound dunite occurs near the crest of a low ridge at a point 
about 2,000 feet southeast of Addie Station, with the best showing about 500 feet south- 
east and up the ridge from the olivine quarry of the Harbison Walker Company. The 
main part of the chromite occurs over an area about 50 feet wide with an additional small 
area occurring about 100 yards to the south along the crest of the ridge. 

The chromite occurs as thickly spaced crystals which in the richer zones give the 
dunite a black banded appearance. The bands trend northeast and southwest with most 
of them dipping about 60° to the southeast. There are several small veins of massive chro- 
mite in the area which bring the content up to about 5 per cent. The richer disseminated 
veins may average about V/o inches in diameter and contain 75 per cent chromite. The 
matrix material is sound granular olivine. Many of the chromite crystals around the 
edges are partly altered to chlorite. An analysis of an average sample of the disseminated 
material including the matrix shows that it contains 1.14 per cent Cr 2 3 . 2 

Under normal conditions it would not be economical to recover chromite from this 
disseminated material. If it ever should become desirable to produce this chromite, it 
should be attempted as a by-product from crushed olivine. 

Placer and residual accumulations of crystals and fragments of chromite occur along 
the small streams and over part of the slopes on the dunite formation northeast of the 

1. Chemical analysis by W. A. Reid, Chemist, Division of Mineral Resources, Department of Conserva- 
tion and Development, Raleigh, N. C. 

2. Analysis by Tennessee Valley Authority Minerals Testing Laboratory, Norris, Tennessee. 



14 Chromite Deposits of North Carolina 



Fisher home. In some of the short and narrow drainage valleys on the formation, this 
placer material in the richer places probably contains 6 per cent chromite by volume. 
The total placer and residual reserve is thought to be less than 500 tons of recoverable 
chromite. 

Chestnut gap Chromite prospect 

A small unimportant chromite prospect occurs in the dunite ring dike one and three- 
fourths miles south of Addie and is exposed in erosion gulches on the Blanton farm a few 
hundred feet north of the farmhouse. This occurrence is on the headwaters of Ocher 
Creek due east of Carver Mountain and about 2,000 feet northeast of Bryson school (see 
Plate 6) . The chromite occurs in a 3-foot shattered zone of dunite about 50 feet west of 
the east contact of the dunite formation. The zone strikes N 38° E and can be traced for 
a distance of about 50 feet. The chromite occurs as small lenses in this shattered area, 
mixed with massive soapstone, impure vein talc, anthophyllite asbestos, and vermiculite. 
The best exposed lens is 15 inches long and 8 inches wide. These small lenses consist of 
talc and small chromite crystals, making up a ground mass around larger chromite crys- 
tals. Some crystals were observed to be Va i ncn or more in diameter. The chromite 
appears to have been crystallized from solution in the shattered zone. The chromite 
formed was later shattered and secondary minerals were introduced into the cracks. 

A few hundred feet down the valley below this chromite occurrence there is a loose 
boulder, 5 feet in diameter, of alternating bands of dunite and disseminated chromite. The 
chromite bands are about one-half inch in diameter and it appears that the chromite makes 
up about 25 per cent by volume of the rock. Each of the bands consists of well-shaped, 
thickly spaced crystals averaging one-tenth inch in diameter. Across the boulder are talc 
seams, at right angles to the chromite bands, with unaltered chromite crystals in the talc 
continuous with the chromite in the boulder. This boulder is of scientific interest regard- 
ing the origin of chromite and talc and its relation to dunite. 

DARK RIDGE CHROMITE PROSPECT 

The Dark Ridge chromite prospect in Jackson County, one and one-half miles south- 
west of Balsam Station, is associated with the Dark Ridge olivine deposits on Dark Ridge 
Creek. The chromite is best exposed in a pit about 900 feet east of the Southern Railroad 
trestle, north of the creek and north of the trail (see Plate 7) . 

This pit, about 25 feet long, 12 feet wide, and 20 feet deep, was made about 1930. It 
is reported that less than 50 tons of chromite was taken out, including one solid lump 
weighing 250 pounds. A ton or more of chiefly massive and very black chromite partly 
banded with olivine remains on the dump. It is reported that the chromite encountered 
occurred as a vein-like lens with a maximum thickness of about two feet and prevailed to 
the bottom of the pit. At the present time the sides have slumped in sufficiently to about 
half fill the pit. Most of the chromite is in direct contact with sound olivine. 

A chipped sample of chromite including matrix taken from the dump gave the fol- 
lowing analysis: 1 

Cr 2 3 Fe 2 O s SiO z Al 2 O s MgO Total Cr:Fe 

39.66 14.18 7.20 26.80 12.34 100.18 2.7:1 



Chemical analysis by W. A. Reid, Chemist, Division of Mineral Resources, N. C. Dept. of Conserva- 
tion and Devel., Raleigh, N. C. 



PLATE 7 




OLIVINE 
MINE 

% 



BALSAM) 



,0 



X 



'<*%> 



'f 



DARK RIDGE 

CHROMITE 

PROSPECT 




Scale 1000 





2000 Feet 
i 



CHROMITE SURVEY JACKSON CO. N.C. 



GEOLOGICAL INVESTIGATION 

DARK RIDGE 

CHROMITE PROSPECT 



N C DEPT OF CONSERVATION AND DEVELOPMENT 

DIVISION OF MINERAL RESOURCES 

AND 

TENNESSEE VALLEY AUTHORITY 

COMMERCE DEPARTMENT 



KNOXVILLE 4-16-4-2 W CO I 82IGI3R0 



Chromite Deposits of North Carolina 



15 



The chromite in this pit appears to have come from a fault zone which probably con- 
tains other similar lenses. Therefore, it is believed that further prospecting in the vicinity 
of the pit would be justified. 

Almost directly across the creek from the pit described above there is a much older 
and smaller pit, which is now about filled and grown over. It is reported by local residents 
that a small pocket of chromite was uncovered in this pit. At the present time small frag- 
ments of chromite remain on the dump. 

Almost due east of the first-described and largest pit, and 200 feet north of the trail, 
a few veins of chromite are exposed in the olivine ledges. The main exposure is a vein ex- 
posed for 15 feet in length and about 5 inches wide, which dips to the north and back into 
the hill. The hanging wall side consists of saxonite and the foot wall is of dunite. The 
chromite is composed of grains less than one-quarter inch in diameter with most of the 
grains separated by kammererite. 

The chromite in the Dark Ridge deposit is associated with good sound olivine, and 
probably the best way to produce chromite from this deposit would be as a by-product 
from olivine production. 

MACON COUNTY 

Corundum hill Chromite prospect 

The Corundum Hill chromite prospect, which is associated with the Corundum Hill 
dunite formation, 1 is located one and one-half miles northwest of Gneiss, Macon County. 
This location is north of Cullasaja River and southeast of Evans Knob (see Plate 8). The 
southern quarter of the Corundum Hill formation contains disseminated chromite probably 
averaging about 2.5 per cent by volume. The chromite crystals, averaging less than one- 
quarter inch in diameter, are well shaped, are a dull, shiny black, and are in a matrix of 
sound olivine. 

The southern slope of Corundum Hill, an area of two or three acres, contains residual 
chromite crystals and fragments derived from weathering of the dunite. The overburden 
is rather thin over the dunite and in places the bare rock is exposed at the surface. This 
overburden of clay probably averages three feet in thickness and appears to contain about 
5 per cent chromite. 

The small stream heading near the deposit contains small amounts of chromite and 
corundum in about equal proportions, in places up to 25 per cent. The material occurs in 
the bottom of the stream and along the sides back for a distance of about 30 feet. In this 
stream the corundum might prove more valuable than the chromite. 

The following results were obtained on a 100 pound sample of the placer material 
taken from the creek bottom: 2 



-f 20 Mesh Concentrate 
CroO, 43.33% 

Fe 23.78 

Insol. 11.48 

Cr:Fe 1.2:1 



— 20 Mesh Concentrate 

Cr.O, 38.59% 

Fe 29.31 
Insol. 9.20 

Cr:Fe 0.8:1 



1. Hunter, Charles E., and Mattocks, Philip W., "Vermiculites of Western North Carolina and North 
Georgia," Tennessee Valley Authority, Division of Geology, Bulletin No. 5 (1936) p. 1. 

2. Beneficiation and chemical analysis made by Tennessee Valley Authority Minerals Testing Laboratory, 
Norris, Tennessee. 



16 Chromite Deposits of North Carolina 



A number of small pieces of massive chromite float have been found along the northern 
contact area. 

ELLIJAY CHROMITE PROSPECT 

The Ellijay chromite prospect (Olivine Deposit Number Nine) 1 is located on Ellijay 
Creek three-fourths mile southwest of Ellijay Post Office, Macon County. The chromite is 
best exposed on the south side of a hill about 1,200 feet east of Ellijay Creek in an outcrop 
of high-grade sound olivine (see Plate 8). The prospect uncovered a small lens of massive 
chromite which was mined during, or shortly after, the war of 1917-18. The opening is 
about 40 feet long, 6 feet wide, and 15 feet deep. The chromite lens is reported to have 
been about 2 feet wide and 12 feet long. Small veins of chromite, approximately 2 inches 
in width, are visible in the side of the cut. The chromite found on the dump consists of 
fine-grained material with occasional crystals one-quarter inch in diameter. Talc and 
chlorite are found between the grains. The massive vein type of ore shows little indica- 
tion of alteration. 

There is a small amount of disseminated chromite in the dunite on the opposite side 
of the hill from the pit. 

Norton Chromite prospect 

The Norton chromite prospect occurs one mile west of Orlando, Macon County. The 
dunite formation with which the chromite is associated lies on the north side and adjacent 
to Commissioner Creek (see Plate 4) . The formation has been greatly altered to amphib- 
olite and outcrops as a steep, but rounded, hill sloping southward toward the creek. The 
southwestern part of the formation contains crystals and blebs of chromite visible all the 
way to the crest of the hill. Near the west contact there is a small amount of magnetite 
mixed with the chromite. 

It is doubtful if there is sufficient concentration of chromite at any one place in the 
formation to permit economical exploitation. However, there may be enough residual 
chromite on part of the weathered surface from which a few hundred tons of chromite 
could be recovered. 

IREDELL COUNTY 

plyler Chromite Prospect 

The Plyler chromite prospect is located about seven miles northeast of Statesville, 
Iredell County. The occurrence, primarily on the Plyler farm one and one-half miles south 
of Turnersburg, is on the south side of the South Fork of Yadkin River. This prospect is 
in the Piedmont area and is about 100 miles east of the other chromite deposits of the 
State. 

The chromite is associated with a large and highly serpentinized dunite mass. The 
formation does not form rough or hilly topography as do the basic ones in the western 
part of the State, but underlies broad low knolls typical of the surrounding country. 

The chromite occurs mainly in the northeastern part of the formation and is best ex- 
posed a few hundred feet south of the Yadkin River. At this point there has been some 



Hunter, Charles E., "Forsterite Olivine Deposits of North Carolina and Georgia," N. C. Dept. Cons, 
and Devel. Bull. No. 41 (1941) p. 100. 



LHI L <J 



4 Elhjay Ch 



ELLIJAY 



tf 




Peak 
Knob 



Hiqdon 



"; Rough Knob 




in/*, Evans 

-<nutKnoi> CORUNDUM HILL 

^\ CHROMITE PROS PEC 
Placer 

Chromite - 




CHROMITE SURVEY, MACON COUNTY. NC 



GEOLOGICAL INVESTIGATION OF 

CORUNDUM HILL AND ELLIJAY 

CHROMITE PROSPECTS 



N C. DEPT OF CONSERVATION AND DEVELOPMENT 

DIVISION OF MINERAL RESOURCES 

AND 

TENNESSEE VALLEY AUTHORITY 

COMMERCE DEPARTMENT 



KNOXVILLE 



4-16-42 



W 



82IGI9 RC 



Chromite Deposits of North Carolina 17 



recent open-pit prospecting at points where there were showings of chromite. The pits are 
about 40 by 50 feet, much larger than the area of exposed chromite. The material taken 
out and stocked averages about 15 per cent chromite. Probably about 100 tons of this dis- 
seminated ore was removed from the cuts, which is a very small proportion to the amount 
of material handled. No attempt was made to follow down on the richer chromite show- 
ing of disseminated or vein material. Most of the chromite encountered was disseminated 
ore that contains both chromite and magnetite in a gangue of talc, chlorite, and serpen- 
tine. The small irregular disseminated chromite zones are too irregular and not closely 
enough connected to mine. 

OTHER CHROMITE LOCALITIES 

There are several other minor occurrences of chromite in western North Carolina. 
None of these are thought to be of any commercial importance. 

Chromite is reported on Cove Creek about seven miles northwest of Boone, Watauga 
County, and in the vicinity of Sapphire, Jackson County. 

Disseminated chromite in olivine occurs on White Oak Creek, one mile southeast of 
Bakersville, Mitchell County. Crystals and blebs of chromite up to one-half inch in 
diameter are visible in much of the olivine exposed on the south side of White Oak Creek. 



MAGNETIC GEOPHYSICAL SURVEY OF THE WEBSTER 
AND DEMOCRAT, N. C, CHROMITE AREAS 

After the principal chromite deposits of North Carolina were examined in detail, 
parts of the Webster and Democrat areas were selected for investigation by geophysical 
methods. These two areas appeared to offer more promise than the other areas for locat- 
ing concealed chromite ore bodies. Through the cooperative agreement between the North 
Carolina Department of Conservation and Development and the Tennessee Valley Author- 
ity, the services of Dr. Gerald R. MacCarthy, Professor of Geology, University of North 
Carolina, were obtained for conducting the magnetic geophysical survey. The following 
report by Dr. MacCarthy covers this survey. 

INTRODUCTION 

The author alone is responsible for the data and opinions set forth in this section of 
the report. Special thanks, however, are due to Dr. F. W. Lee and to Dr. J. H. Swartz of 
the United States Geological Survey, who offered many helpful suggestions, especially in 
regard to the interpretation of the data. 

GEOPHYS8CS 

Geophysics may be defined as the application of physics to the solution of geological 
problems. Every rock and mineral species has certain physical properties which, while 
more or less constant for each species, differ considerably from one species to another. 
Among these physical properties are density (or specific gravity) , elasticity, electrical con- 
ductivity, and magnetic permeability. Each of these properties has been used as the basis 
of a specific method of geophysical prospecting. 

Seismic prospecting, widely used in the petroleum industry, is based upon the elastic 
properties of earth materials. Gravitational prospecting is also much used by the oil 
industry. It is based upon density differences. Electrical prospecting is based upon dif- 
ferences in rock conductivities, upon the presence of natural earth currents, and the like. 
Magnetic prospecting is based upon differences in the magnetic susceptibility of the 
different rocks and minerals. 

No geophysical method — used by itself — can be relied upon to give a complete and 
accurate picture of underground conditions. In all cases the geophysical data must be 
supplemented by, and studied in connection with, geological data. The combination of 
geology and geophysics always proves to be a far more accurate tool than either method 
used alone. 

Magnetic Methods 

All substances are more or less magnetic, although only iron, cobalt, and nickel, to- 
gether with certain of their compounds, are strikingly so. Were the materials composing 
the crust of the earth entirely uniform in their magnetic properties, the earth's magnetic 
field would also be uniform, and would change from one place to another in a perfectly 
regular fashion. But, because of the varying magnetic properties of the rocks and min- 
erals which make up the earth's crust, the earth's magnetic field is not at all uniform. In 



Chromite Deposits of North Carolina 19 



fact, it is highly irregular. Since these local magnetic irregularities or "anomalies" are 
caused by the presence of different rocks and minerals in a given region, a study of the 
magnetic anomalies frequently will give a clue to the geology of the region. 

For certain technical reasons the total strength of the earth's field is rarely deter- 
mined, usually only changes in the intensity of its vertical component are measured by 
field magnetometers. 

Magnetic anomalies are of two general kinds. A rock formation or ore body which has 
a higher magnetic susceptibility than that of the surrounding material will cause a mag- 
netic "high" by intensifying the earth's field in its immediate neighborhood, while one 
possessing a lower than average susceptibility will cause a magnetic "low". Polarized 
formations are also found. Such formations are not simply magnetic; they have been 
magnetized so that they behave as though they were actual bar magnets and exhibit 
definite north and south poles. An example of such a polarized formation is found on the 
map of the North Part of the Democrat Chromite Area with the positive pole near coordi- 
nates B: 4.25, and the negative pole near coordinates B: 3.10 (see Plate 17). 

It should be noted that while magnetic anomalies serve to locate the position of under- 
ground features quite accurately as far as their geographic position goes, it is often diffi- 
cult to distinguish between a small magnetic disturbance close to the surface and a large 
one at a greater depth. In this respect magnetic and electrical prospecting serve to com- 
plement each other, for while the various methods based upon electrical conductivity fre- 
quently give accurate depth determinations, they do not, as a rule, fix the geographical 
position as closely as does the magnetic method. When dealing with an occurrence which 
gives both magnetic and electrical indications, the ideal method of attack would be to 
locate first the geographical position of the anomalies by means of the magnetometer, and 
then resurvey certain selected portions of the field by electrical means. Unfortunately, 
any of the electrical methods requires far more apparatus, demands a larger crew of men, 
and is much more expensive than a magnetic survey of the same area. For these reasons 
no electrical work has been done so far in the North Carolina chromite areas. 

Chromite, which is somewhat variable in its chemical composition, is also variable in 
its magnetic behavior, since the latter depends, to a large extent, upon the former. Some 
specimens are quite magnetic, while most of them are less magnetic than the rocks in 
which they are found. Chromite may therefore give rise either to magnetic "highs" or to 
magnetic "lows", although the latter is the more usual case. This is because clunite, the 
rock with which chromite is almost always associated, is in itself extremely magnetic for a 
rock. Even when the chromite differs too little in susceptibility from the surrounding rock 
to give usable anomalies, the bodies of intrusive rock in which the chromite deposits are 
located may be outlined by means of the magnetometer although concealed by many feet 
of overburden. This is especially well shown in the Webster chromite area. A compari- 
son of the geologic map (see Plate 9) with either the cardboard model (see Plate 10) or the 
"isogamic" map (see Plate 13) shows that the contacts of the dunite intrusion with the 
surrounding country rock were located by the magnetometer with great accuracy, as was 
the presence of such features as a large quartz vein, and other bodies of quartz and talc 
whose presence was confirmed by "float". 



20 Chromite Deposits of North Carolina 



The following table shows the magnetic susceptibilities 1 of certain rocks and minerals. 2 
The mineral magnetite has a susceptibility of about 300,000 x 106 units. 

Rock or Mineral Magnetic Susceptibility 

Quartz —1.07 to —1.2 

Serpentine 10.87 

Ilmenite 30,740 to 252,000 

Chromite (Asia Minor) 244.51 

Hematite 40 to 100 

Limonite 100 to 220 

Gneiss (various) 10 to 2000 

Talcose slate (Urals) 3000 

Pyrrhotite (Sudbury) 125,000 

Serpentine (Harz) 254 

Serpentine (Urals) 14,100 

Schist (Oberharz) 115 

Magnetite, pyrrhotite, and ilmenite are the only extremely magnetic minerals com- 
monly met with. While both magnetite and ilmenite were seen, no pyrrhotite was 
recognized during these investigations. 

In most cases it is the amount of magnetite or ilmenite contained in a rock which 
governs its susceptibility and, since many of the igneous and metamorphic rocks vary 
greatly from specimen to specimen in the amount of these minerals which they carry, no 
one figure for susceptibility can be applied to all specimens of the same rock type. 

In both the Webster and the Democrat areas the chromite is associated with the rock 
dunite. Dunite is a more or less pure olivine rock, usually containing scattered crystals of 
either magnetite or chromite. In North Carolina much of the dunite has been partially 
altered to serpentine, and therefore, from the table above, we may take its magnetic sus- 
ceptibility as ranging somewhere between 254 and 14,100 units. Chromite, as listed in 
the table, has a susceptibility of only 245 units, and hence is definitely less magnetic than 
the rock with which it is intimately associated. A chromite ore body should therefore 
show on a magnetic map as a weak "low", and this relation was noted in all cases where 
the presence of chromite has been definitely proved. If we were dealing with serpentinized 
dunite and chromite alone, without the further complication of the presence of such highly 
magnetic materials as magnetite and ilmenite, it should be easy to locate all chromite ore 
bodies with little trouble. But such is not the case ; both at Webster and at Democrat the 
picture is confused by the presence of these highly magnetic minerals which more or less 
mask the presence of the weakly magnetic chromite. Therefore only those chromite ore 
bodies which are not too closely associated with magnetite or ilmenite can be recognized as 
such by magnetic means. 

An example of a magnetic high caused by the mineral magnetite may be seen on the 
"isogamic" map of the southeast part of the Webster area. The small but intense high 
located near coordinates D-40: 1.25 was excavated, and a quantity of chlorite schist con- 
taining visible dense, black crystals found. The black crystals were later found to be 



1. Magnetic susceptibility is merely a numerical expression indicating how magnetic a given substance 
is. For present purposes it is sufficient to remember that the higher the value of the susceptibility, 
the more magnetic the material. 

2. As given by C. A. Heiland in "Geophysical Exploration," New York: Prentice-Hall, 1940, pp. 310 et seq. 



Chromite Deposits of North Carolina 21 



magnetite and ilmenite, with the latter predominating. The chlorite schist, when crushed 
and panned, furnished slightly more than 5 per cent of heavy minerals, of which about 20 
per cent appeared to be magnetite and the rest ilmenite. Chromite could not have been 
present in any appreciable quantity, since no chromium reaction was obtained either from 
the crystals or from the rock itself. 1 

In both the Webster and the Democrat areas every known occurrence of chromite 
gives rise to a weak magnetic low. Unfortunately, these lows are by no means the most 
striking features of the magnetic picture. Nevertheless, they are distinct enough and form 
sufficiently definite patterns to indicate with a considerable degree of probability both the 
further extension of known ore bodies, and the possible existence of hitherto undiscovered 
pockets of chromite. The presence of a weak magnetic low, similar to the lows which 
occur in association with known bodies of chromite, does not prove the existence of a 
chromite pocket beneath it; it merely indicates that such an area is worthy of further 
investigation, and that it should be trenched or drilled. Where no such lows are present 
the probability of chromite being present is very slight, and further investigations of such 
areas should be postponed until all the more favorable localities have been tested. 

PROCEDURE 

In both the Webster and Democrat areas rectangular grids were laid out by means of 
the transit. Magnetometer readings were taken at definite intervals along these coordinate 
lines. Over much of the area readings were also taken along more closely spaced lines, 
parallel to those of the main grid. These grids are described in more detail by T. G. 
Murdock. 2 

No attempt was made to reduce the magnetometer readings to their absolute values. 
Instead, a station was arbitrarily chosen as the base station, its value assumed to be zero, 
and all readings referred to it. Thus, if "800 gammas" is recorded for a certain station, 
it is to be understood that the reading at that station was 800 gammas higher than at the 
base station, with no implication of the absolute value at either point. Likewise, a re- 
corded value of "minus 1,000 gammas" merely means that at that point the reading was 
1,000 gammas lower than at the base station. 

All readings were taken by means of the Askania "Schmidt Type Vertical Field 
Balance", and were reduced to gammas 3 before being plotted. For purposes of further 
study the data obtained in each of the three areas were used in the construction of three 
dimensional models of the "egg-crate" type. (See photographs of these models, Plates 13, 
14, 15, 18, and 20). Each magnetic traverse was plotted on cross-section paper, using 
the same horizontal scale as was used in constructing the geologic maps, transferred to 
stiff cardboard, and the latter cut to follow the plotted curves. These cardboard strips, 
when set up along the lines of the traverses, form the models. Several "isogamic maps" 
were also constructed to illustrate portions of the areas in a more familiar manner. An 



1. Determinations made by William Rice of the University of North Carolina. 

2. Murdock, T. G., "Horizontal Control — Webster and Democrat, N. C. Chromite Investigation," R. I. 24 
and 25, Division of Mineral Resources, N. C. Dept. of Conservation and Development, Raleigh, N. C. 

3. A gamma is the one-hundred thousandth of the gauss, the fundamental magnetic unit. The total 
strength of the earth's field is about 50,000 gammas, or half a gauss, so that an anomaly of 10,000 
gammas means a local variation in the earth's field of one part in five, or 20 percent. 



22 Chromite Deposits of North Carolina 



isogamic map is similar to the familiar "contoured" topographic map, except that the 
"contour lines" are drawn through points of equal magnetic readings instead of through 
points of equal elevation above sea level as is done in constructing a topographic map. 
(See Plate 10.) 

WEBSTER AREA « 

MAGNETIC SURVEY 

Plate 9 is a geologic map of the area near Webster, North Carolina, which was sur- 
veyed; Plates 10, 11, and 12 are isogamic maps of portions of the same area; and Plates 
13, 14, and 15 are photographs of the egg-crate model. 1 The general features of the area 
are perhaps best exhibited by the model. Along the northern margin of the model the 
flat "magnetic plateau" indicates the presence of the rather homogeneous schists which 
occupy that area. South of the schists is ah irregular linear high which extends across 
the model in a roughly east-west direction. This "contact high" lies along the northern 
boundary of the dunite intrusion and is apparently caused by the presence of iron-bearing 
minerals concentrated along the contact zone. Only weathered specimens were available 
for study, and the predominant iron mineral was limonite. The limonite, which is only 
weakly magnetic, was doubtlessly formed by the alteration of magnetite or ilmenite still 
present at greater depths, as is indicated by the high magnetic readings obtained along 
this contact zone. A less continuous but still well-marked low which lies between the 
schists and the contact high follows in part a zone of talc and in part a rather wide vein of 
massive quartz. 

The relatively featureless southern margin of the model represents the rather uniform 
hornblende gneiss and schists which border the dunite in that direction and, especially in 
the southeast portion of the model, another contact high, similar to the one along the north 
border, indicates a discontinuous zone of magnetic chlorite and amphibolites which sepa- 
rates the gneisses from the dunite. An extremely magnetic mass of chlorite, whose mag- 
netism is derived from the contained magnetite and ilmenite, was found to underlie the 
enormous high which stands out so prominently near the southeast corner of the model. 
(See Page 41.) 

The dunite intrusion with which the chromite is associated occupies the central and 
less strikingly irregular portion of the model between the two contact highs. 

Exact comparison of the geologic map and the magnetic model can best be made by 
actually superimposing the model directly upon the map. However, by carefully noting the 
map coordinates of the various features, more or less exact comparisons can be made from 
the illustrations accompanying this report. 

Each of the maps, as well as the model, carries the same set of coordinates. The main 
north-south lines of the grid, 100 feet apart, are numbered consecutively from east to 
west, to 13. The intermediate north-south lines, spaced 25 feet apart, are given the num- 
ber of that main line of the grid which lies immediately to their east, plus a decimal indi- 
cating the number of feet separating them. Thus line 2.25 is that intermediate line which 
is parallel to, and 25 feet west of line 2 of the main grid ; line 12.75 is the one which is 



1. Geologic maps were made by Charles E. Hunter; models and isogamic maps were made by G. R. Mac- 
Cartby. 



PLATE 9 




GEOLOGICAL 

AND 

GEOPHYSICAL INVESTIGATION 



TENNESSEE VALLEY AUTHORITY 

COMMERCE DEPARTMENT 

AND 

N C DEPARTMENT OF CONSERVATION & DEVELOPMENT 

DIVISION OF MINERAL RESOURCES 



KNOXVILLE 



10-24-41 W CO I 82ID3 R.O. 



22 Chromite Deposits of North Carolina 



isogamic map is similar to the familiar "contoured" topographic map, except that the 
"contour lines" are drawn through points of equal magnetic readings instead of through 
points of equal elevation above sea level as is done in constructing a topographic map. 
(See Plate 10.) 

WEBSTER AREA ■ 

Magnetic Survey 

Plate 9 is a geologic map of the area near Webster, North Carolina, which was sur- 
veyed; Plates 10, 11, and 12 are isogamic maps of portions of the same area; and Plates 
13, 14, and 15 are photographs of the egg-crate model. 1 The general features of the area 
are perhaps best exhibited by the model. Along the northern margin of the model the 
fiat "magnetic plateau" indicates the presence of the rather homogeneous schists which 
occupy that area. South of the schists is ah irregular linear high which extends across 
the model in a roughly east-west direction. This "contact high" lies along the northern 
boundary of the dunite intrusion and is apparently caused by the presence of iron-bearing 
minerals concentrated along the contact zone. Only weathered specimens were available 
for study, and the predominant iron mineral was limonite. The limonite, which is only 
weakly magnetic, was doubtlessly formed by the alteration of magnetite or ilmenite still 
present at greater depths, as is indicated by the high magnetic readings obtained along 
this contact zone. A less continuous but still well-marked low which lies between the 
schists and the contact high follows in part a zone of talc and in part a rather wide vein of 
massive quartz. 

The relatively featureless southern margin of the model represents the rather uniform 
hornblende gneiss and schists which border the dunite in that direction and, especially in 
the southeast portion of the model, another contact high, similar to the one along the north 
border, indicates a discontinuous zone of magnetic chlorite and amphibolites which sepa- 
rates the gneisses from the dunite. An extremely magnetic mass of chlorite, whose mag- 
netism is derived from the contained magnetite and ilmenite, was found to underlie the 
enormous high which stands out so prominently near the southeast corner of the model. 
(See Page 41.) 

The dunite intrusion with which the chromite is associated occupies the central and 
less strikingly irregular portion of the model between the two contact highs. 

Exact comparison of the geologic map and the magnetic model can best be made by 
actually superimposing the model directly upon the map. However, by carefully noting the 
map coordinates of the various features, more or less exact comparisons can be made from 
the illustrations accompanying this report. 

Each of the maps, as well as the model, carries the same set of coordinates. The main 
north-south lines of the grid, 100 feet apart, are numbered consecutively from east to 
west, to 13. The intermediate north-south lines, spaced 25 feet apart, are given the num- 
ber of that main line of the grid which lies immediately to their east, plus a decimal indi- 
cating the number of feet separating them. Thus line 2.25 is that intermediate line which 
is parallel to, and 25 feet west of line 2 of the main grid; line 12.75 is the one which is 



1. Geologic maps were made by Charles E. Hunter; models and isogamic maps were made by G. R. Mac- 
Cartby. 




|i.-«-.i HcolllB2ID3.» 



PLATE 10 




CHROMITE SURVEY - WEBSTER, N C 



GEOPHYSICAL INVESTIGATION 
MAGNETIC MAP 



NC DEPARTMENT OF CONSERVATION 8. DEVELOPMENT 

DIVISION OF MINERAL RESOURCES 

AND 

TENNESSEE VALLEY AUTHORITY 

COMMERCE DEPARTMENT 



KNOXVILLE 



11-3-41 



W CO I '82 I D4 




NW PART OF WEBSTER, NC CHROMITE AREA 



CHROMITE SURVEY -WEBSTER, N C 



GEOPHYSICAL INVESTIGATION 
MAGNETIC MAP 



8;ma - 




/vores 

ass yz? t &z^z£»~r 

shown by dashed lines 

TarfoZltT ^^ mdde With Askani * *>"*•' 



Scale 10 



10 



20 Feet 



CHROMITE SURVEY-WEBSTER, N. C. 



GEOPHYSICAL INVESTIGATION 
MAGNETIC MAP 



N C DEPARTMENT OF CONSERVATION 4 DEVELOPMENT 
DIVISION OF MINERAL RESOURCES 

AND 

TENNESSEE VALLEY AUTHORITY 
COMMERCE DEPARTMENT 



KNOXVILLE 



'-2-42 W [C0| I 1 82IR4-? g 




SOUTHEAST PART OF WEBSTER N C CHROMITE AREA 



I 1-2-42 Iwlcol i!B2IB4-2r 




1100 






xOO 



NOTES 

Contours are isogams drawn at 50 and 100 gamma 

intervals Where used, SO gamma contours are 

shown by dashed lines. 

Observations were made with Askanla Vertical 

Variometer 



Scale 10 

I B H H M l-l 



10 



20 Feet 



^ 



CHROMITE SURVEY-WEBSTER, N C 



GEOPHYSICAL INVESTIGATION 
MAGNETIC MAP 



N C DEPARTMENT OF CONSERVATION & DEVELOPMENT 
DIVISION OF MINERAL RESOURCES 



TENNESSEE VALLEY AUTHORITY 
COMMERCE DEPARTMENT 



KNOXVILLE 



■2-42 W CO! I 821 B4-3^ 




'ontours are uogams drawn at SO and 100 gamma 
nttrvaU Where used. SO gamma contours ara 
hown 6y dashed hnes 

Scale 1 10 20 Feet 

CMROMITE SURVEY-WEBSTER, N- C. 

GEOPHYSICAL INVESTIGATION 
MAGNETIC MAP 



NORTHEAST PART OF WEBSTER N C CHROMITE AREA 



: |w|co| i 1821B4-3* 



PLATE 13 



<S) 



O 



ca 




IX 
< 





O 




y 



■si 



? ^ C 






PLATE 14 




"0 



c^ 



C\i 



r> 



PLATE 15 




Chkomite Deposits of North Carolina 23 



parallel to, and 75 feet west of, line 12, etc. The east-west lines of the main grid were 
given consecutive letters of the alphabet, starting with "D" on the south, and ending with 
"I" on the north. 1 The expression C-50 indicates an east-west line 50 feet north of line C, 
G-96 one 96 feet north of line G, etc. Thus the small but very intense high already men- 
tioned as lying near the southeast corner of the grid has its center near the point whose 
coordinates are D-40: 1.25. 

INTERPRETATION OF RESULTS 

As has already been mentioned, the most striking features of the magnetic picture are 
not the chromite ore bodies, but the sharply defined borders of the clunite intrusion, a talc- 
quartz vein which roughly follows line "H" along the northern border of the eastern half 
of the area, and the so-called border highs. These latter do not seem to be in any way 
associated with the presence of chromite, but of magnetite and ilmenite which appear to 
be strongly concentrated in these areas. 

A rather sharply defined magnetic trough which starts near G-50: 7.00 and extends 
southeasterly through F-90 : 6.25 seems to indicate some form of geologic structure — per- 
haps a fault — whose presence cannot be otherwise detected, since the available exposures 
are insufficient. While certain of the magnetic lows, such as the one centering at G-80: 
9.20 might perhaps indicate the presence of chromite, it appears more likely that they are 
simply a result of slight variations in the country rock itself. 

An interesting feature is the long magnetic trough which extends eastward from 
about G-80: 10.25 to G-80: 9.50, where it swings southeastward to G-65: 9.10, from which 
it continues nearly due east to about G-60: 9.75. This trough appeared to indicate a pos- 
sible extension of the ore found in the series of pits and shafts near the northern boundary 
of the area. However, five drill holes in this general area (see section of this report on 
"Core Drilling Chromite Prospect, Webster, N. C.) failed to find more than about 10 per 
cent chromite except at holes "D" and "F" where pockets of 60 per cent and 25 per cent 
chromite respectively were encountered. From the drill logs, 3 per cent chromite would 
seem to be about the average figure. As has already been said, the magnetic method 
allows of no very exact depth determinations; therefore, the drill holes were all started 
outside of the magnetic indications, and run in at an angle so as to intersect the vertical 
plane passed through the axis of the magnetic trough at some depth. In this way it was 
hoped that the maximum amount of information might be obtained. While the results 
of the drilling are far from encouraging, it is still entirely possible that pockets of 
chromite may be present along the axis of the magnetic trough either above or below the 
point of intersection with the drill holes. One or two vertical holes, drilled over the inter- 
section of hole "D" or "F" with the vertical plane passed through the axis of the magnetic 
trough at about G-75: 11.00 and G-60: 8.75, might give additional information on this 
point. Hole "E" intersected the narrow disseminated chromite zone occurring under the 
cut to the northeast. The circular "low" centering near G-25: 7.90 a short distance south 
of hole "E" was not drilled because of the difficulty encountered in drilling hole "E". 

In the southeast part of the area the magnetic low which may be associated with the 
chromite exposed in the cut at about E-00: 1.50 to E-00: 1.80 swings somewhat toward the 



1. Lines A, B, and C were laid out, but were not used. 



24 Chromite Deposits of North Carolina 



northwest and crosses the 2.00 line at about E-20, whereas the excavation turns the other 
way, suggesting that the chromite body splits somewhere near the western end of the 
working. It might be worth while to extend the cut along the axis of the low northwest 
from E-00: 1.80 to about E-00: 2.00. The series of small, more or less continuous lows 
along the "E" line just north of the southern border highs in the southeastern part of 
the area from 1.75 to 2.75 (perhaps to 3.75) seems also to be worth investigating, as 
might also the low located at approximately E-50: 4.00, where some massive chromite 
float was found. 

None of the large, subcircular lows, such as those mapped in the northwest part of 
this area, appear as favorable as those just mentioned. The two drill holes ("C" and "E") 
near these circular "lows" showed greater than average depth to bedrock, and it may well 
be that the extra depth of weathered material present at these points is responsible for 
the lows. 1 Were it not for the fact that it appears to lie outside of the dunite area, the 
long, continuous, small low running approximately along the H-25 line from 7.50 to 10.50 
would appear to be well worth investigating. The only other favorable indication in this 
area is the small low at about G-25 : 12.25. All these localities are located on the geologic 
map (see Plate 9). 

RECOMMENDATIONS 

In view of the results obtained by the six holes already drilled, no strong recommen- 
dations for further exploratory work can be made. However, it should be pointed out that 
none of the pits and shafts so far dug are deep enough to give a very clear picture of the 
form and size of the ore bodies. If they are in the form of definite sheet veins, the angle 
holes already drilled should have intersected them at depth. If, on the contrary, they are 
in the form of more or less separate lenticular masses, the angle holes may very well have 
missed any ore body present by passing either above or below it. Before the prospect is 
definitely abandoned, several more drill holes should be sunk along the magnetic indica- 
tions, this time as vertical, rather than as angle, holes. In view of the fact that in the 
magnetic latitude of North Carolina magnetic indications are offset southward by an 
amount which is approximately 10 per cent of the depth to the objects which produce 
them, it might be well to locate all vertical drill holes 8 to 10 feet north of the centers of 
the indications which are being tested. Or, what amounts to the same thing, instead of 
being exactly vertical, the drill holes might be started in the centers of the indications, and 
slanted northward at an angle of about 85 degrees to the horizontal. It is further recom- 
mended, that if any drilling is done at either of the Democrat areas or additional drilling 
at Webster, both vertical and angle holes be tried. 

DEMOCRAT AREA 

At Democrat there are two more or less distinct chromite-bearing areas, separated 
by a large mass of pegmatite. The more northerly portion of this chromite deposit is here 
referred to as the "North Democrat Area" and the more southerly part as the "South 
Democrat Area". 



This suggestion was made by T. G. Murdock, of the N. C. Department of Conservation and Develop- 
ment. 



SMALL 

CHROMITE VEINS 



SERPENTINIZED DUNITE CONTAINING 
DISSEMINATED CHROMITE IN WHOLE 
,HYDRAULICED AREA 

.uLL 




i_x 



8 7 6 5 4 3 

SOUTHERN PART OF DEMOCRAT CHR 




re. a. 



DEPOSIT 



Scale 25 



25 



50 Feet 



CHROMITE SURVEY - DEMOCRAT.N C 



GEOLOGICAL 

AND 

GEOPHYSICAL INVESTIGATION 



TENNESSEE VALLEY AUTHORITY 

COMMERCE DEPARTMENT 

AND 

N C DEPARTMENT OF CONSERVATION & DEVELOPMENT 

DIVISION OF MINERAL RESOURCES 



KNOX VI LI F 



IO-PI- 41 



Iw Ir.oi i ft? I K25-: 



24 Chromite Deposits of North Carolina 



northwest and crosses the 2.00 line at about E-20, whereas the excavation turns the other 
way, suggesting that the chromite body splits somewhere near the western end of the 
working. It might be worth while to extend the cut along the axis of the low northwest 
from E-00: 1.80 to about E-00: 2.00. The series of small, more or less continuous lows 
along the "E" line just north of the southern border highs in the southeastern part of 
the area from 1.75 to 2.75 (perhaps to 3.75) seems also to be worth investigating, as 
might also the low located at approximately E-50: 4.00, where some massive chromite 
float was found. 

None of the large, subcircular lows, such as those mapped in the northwest part of 
this area, appear as favorable as those just mentioned. The two drill holes ("C" and "E") 
near these circular "lows" showed greater than average depth to bedrock, and it may well 
be that the extra depth of weathered material present at these points is responsible for 
the lows. 1 Were it not for the fact that it appears to lie outside of the dunite area, the 
long, continuous, small low running approximately along the H-25 line from 7.50 to 10.50 
would appear to be well worth investigating. The only other favorable indication in this 
area is the small low at about G-25: 12.25. All these localities are located on the geologic 
map (see Plate 9). 

recommendations 

In view of the results obtained by the six holes already drilled, no strong recommen- 
dations for further exploratory work can be made. However, it should be pointed out that 
none of the pits and shafts so far dug are deep enough to give a very clear picture of the 
form and size of the ore bodies. If they are in the form of definite sheet veins, the angle 
holes already drilled should have intersected them at depth. If, on the contrary, they are 
in the form of more or less separate lenticular masses, the angle holes may very well have 
missed any ore body present by passing either above or below it. Before the prospect is 
definitely abandoned, several more drill holes should be sunk along the magnetic indica- 
tions, this time as vertical, rather than as angle, holes. In view of the fact that in the 
magnetic latitude of North Carolina magnetic indications are offset southward by an 
amount which is approximately 10 per cent of the depth to the objects which produce 
them, it might be well to locate all vertical drill holes 8 to 10 feet north of the centers of 
the indications which are being tested. Or, what amounts to the same thing, instead of 
being exactly vertical, the drill holes might be started in the centers of the indications, and 
slanted northward at an angle of about 85 degrees to the horizontal. It is further recom- 
mended, that if any drilling is done at either of the Democrat areas or additional drilling 
at Webster, both vertical and angle holes be tried. 

DEMOCRAT AREA 

At Democrat there are two more or less distinct chromite-bearing areas, separated 
by a large mass of pegmatite. The more northerly portion of this chromite deposit is here 
referred to as the "North Democrat Area" and the more southerly part as the "South 
Democrat Area". 



1. This suggestion was made by T. G. Murdock, of the N. C. Department of Conservation and Develop- 
ment. 




SOUTHERN PART OF DEMOCRAT CHROMITE DEPOSIT 




1 8 9 10 II 12 13 II 

NORTHERN PART OE DEMOCRAT CHROMITE DEPOSIT 



25 50 Feci 






E3-— — — 



CHROMITE SURVEY-DEMOCRAT.N C 



GEOLOGICAL 

AND 

GEOPHYSICAL INVESTIGATION 



I"-'-" l-vle°hle2IK2.» 



Chromite Deposits of North Carolina 25 



NORTH DEMOCRAT AREA 

For this area a grid composed of lines spaced 25 feet apart was laid out. The south- 
west-northeast series was lettered from A to N, starting at the northwest boundary of 
the areas; the northwest-southeast series was numbered from to 17, starting at the 
southwest boundary of the area. Magnetic traverses were run along the numbered lines, 
with observations taken every 10 feet except where wire fences, pipelines, etc., interfered. 

Several old prospect pits and trenches, together with the hydraulic operations which 
were going on at the time of the survey, gave excellent exposures over much of the area. 
An iron pipe which carried water to the hydraulic monitor, and several barbed wire fences 
constituted enough magnetic interference so that certain portions of the region could not 
be covered completely by the survey. Aside from these areas of interference, traverses 
were run along the "north-south" lines with observations every ten feet, so that the mag- 
netometer readings were taken at the intersections of a 10-by-25-foot grid. 

Only two regions of marked magnetic contrast were found in this area. Near the east 
corner of the area a region of intense magnetism was encountered, with maximum anom- 
alies of plus 17,790 and minus 20,566 gammas, a total range of 48,355 gammas. While 
no large masses of magnetite were seen, such anomalies could be due only to the presence 
of this mineral, while the positive and negative poles shown on the isogamic map (see 
Plate 17) indicate that the magnetite is not only magnetic, but is actually polarized, that 
is, exists as a natural magnet, or lodestone. A second pair of magnetic poles, but of much 
less intensity, was found along the "B" line between 3.00 4.10. Here the total anomaly was 
only about 3500 gammas. 

No distinct border highs, like those found at Webster, were found. 

INTERPRETATIONS AND RECOMMENDATIONS 

In general, the magnetic indications in this area are less favorable than at Webster. 
The most promising indications are found along the lines of existing trenches and pits, 
say from about E : 3.00 to F-10 : 7.00 to F : 10.00 to E : 12.00. However, these indications 
may be in part due to the removal of residual soil during earlier mining operations, and 
only in part to the presence of chromite. Although the relative importance of these factors 
cannot be assumed with any degree of assurance, it would seem that there may be some 
chance of finding chromite in place along this line. A vertical drill hole inside the area 
enclosed by the 800 gamma line which centers at about E: 4.00 might possibly show 
chromite, and the low extending almost due south from about F : 7.00 might also bear in- 
vestigation. The low at E : 12.00 appears to be too "deep" to be of much value, although 
a prospect pit at this point might show something. The small highs on the "H" line at 
about 12:00 and 13:00 may perhaps be associated with the "vertical fault filled with 4" 
chromite vein" shown on the geologic map as lying just west of them (see Plate 16), 
although the highs are probably not due to chromite. 

Aside from closer examination of the points mentioned above, no recommendations for 
further trenching or drilling can be given on the basis of the magnetic data, and it would 
appear that this area must remain primarily a placer prospect. 



26 Chkomite Deposits of North Carolina 

SOUTH DEMOCRAT AREA 

MAGNETIC SURVEY 

A primary grid, spaced at 25-foot intervals, was laid out, with the lines parallel to 
those of the North Democrat area. The northeast-southwest lines were lettered from "A" 
to "I", starting with the southeastern border of the area, and the northwest-southeast 
lines were numbered from "0" to "8" starting with the northeast border of the area. Mag- 
netometer readings were taken at 10-foot intervals along lines parallel to those of this 
primary grid, but spaced 10 feet apart, so that a complete set of readings located at the 
corners of 10-foot squares was obtained. Plate 19 is an isogamic map and Plate 20 is a 
photograph of the cardboard model constructed for this region. 

INTERPRETATIONS AND RECOMMENDATIONS 

Although no particularly favorable indications were obtained in this area, these locali- 
ties might be worth further investigation: (1) the small low just northeast of the "1.00" 
line, and centering around "D", with perhaps an extension toward E: 0.10. This may be 
connected with the "disseminated chromite in dunite" shown just west of it on the geologic 
map. (2) The small low just south of the high near G: 2.20 in the northwest corner of 
the model, and running approximately from F : 2.10 to G : 2.30. However, this low may be 
associated with the "nickel prospect trench" shown on the geologic map, rather than with 
chromite. (3) The small low centering nearE: 2.20 and extending about 20 feet to the 
east of that point may be connected with the "small chromite seams" shown near E: 2.15 
on the geologic map. (4) The low extending from D: 4.30 to G: 6.20 also appears to be of 
some interest, but since it lies within the area where hydraulic operations have been car- 
ried out, it may be the result of these activities rather than being caused by the presence 
of chromite. 

GENERAL CONCLUSIONS 

In neither the Webster nor the Democrat areas were any extremely good indications 
of chromite ore bodies obtained. In the Democrat areas little, if any, further exploratory 
work can be recommended, although the areas mentioned above might bear further in- 
vestigation. In the Webster area slightly more favorable indications were obtained, and 
two or three more drill holes, located as recommended, seem to be called for. 

CORE DRILLING OF WEBSTER CHROMITE PROSPECT 

Results of the geological investigations of the chromite deposits in western North 
Carolina indicated that the areas near Webster and Democrat were the most likely to be 
of commercial value. These areas were studied in detail, and magnetic geophysical sur- 
veys were made on selected parts of each area. Results of such surveys indicated the 
location of probable chromite deposits. With these data as a basis, the northwestern 
section of the Webster area appeared to have the greatest concentration of chromite, and 
therefore was selected for core drilling. 

The purpose of the core drilling was to determine whether the magnetic anomalies 
found in the geophysical survey indicated the existence of underlying chromite bodies. In 
addition, it was hoped that the core drilling would aid in determining the extent of the con- 



J. 00 JO 




-">oo. 



CHROMITE SURVEY-DEMOCRAT. N. C. 



GEOPHYSICAL INVESTIGATION 
MAGNETIC MAP 



N C DEPARTMENT OF CONSERVATION & DEVELOPMENT 
DIVISION OF MINERAL RESOURCES 

AMD 

TENNESSEE VALLEY AUTHORITY 
COMMERCE DEPARTMENT 



~T 



\7 



26 Chkomite Deposits of North Carolina 

SOUTH DEMOCRAT AREA 

Magnetic survey 

A primary grid, spaced at 25-foot intervals, was laid out, with the lines parallel to 
those of the North Democrat area. The northeast-southwest lines were lettered from "A" 
to "I", starting with the southeastern border of the area, and the northwest-southeast 
lines were numbered from "0" to "8" starting with the northeast border of the area. Mag- 
netometer readings were taken at 10-foot intervals along lines parallel to those of this 
primary grid, but spaced 10 feet apart, so that a complete set of readings located at the 
corners of 10-foot squares was obtained. Plate 19 is an isogamic map and Plate 20 is a 
photograph of the cardboard model constructed for this region. 

INTERPRETATIONS AND RECOMMENDATIONS 

Although no particularly favorable indications were obtained in this area, these locali- 
ties might be worth further investigation: (1) the small low just northeast of the "1.00" 
line, and centering around "D", with perhaps an extension toward E : 0.10. This may be 
connected with the "disseminated chromite in dunite" shown just west of it on the geologic 
map. (2) The small low just south of the high near G: 2.20 in the northwest corner of 
the model, and running approximately from F: 2.10 to G: 2.30. However, this low may be 
associated with the "nickel prospect trench" shown on the geologic map, rather than with 
chromite. (3) The small low centering near E : 2.20 and extending about 20 feet to the 
east of that point may be connected with the "small chromite seams" shown near E : 2.15 
on the geologic map. (4) The low extending from D : 4.30 to G : 6.20 also appears to be of 
some interest, but since it lies within the area where hydraulic operations have been car- 
ried out, it may be the result of these activities rather than being caused by the presence 
of chromite. 

GENERAL CONCLUSIONS 

In neither the Webster nor the Democrat areas were any extremely good indications 
of chromite ore bodies obtained. In the Democrat areas little, if any, further exploratory 
work can be recommended, although the areas mentioned above might bear further in- 
vestigation. In the Webster area slightly more favorable indications were obtained, and 
two or three more drill holes, located as recommended, seem to be called for. 

CORE DRILLING OF WEBSTER CHROMITE PROSPECT 

Results of the geological investigations of the chromite deposits in western North 
Carolina indicated that the areas near Webster and Democrat were the most likely to be 
of commercial value. These areas were studied in detail, and magnetic geophysical sur- 
veys were made on selected parts of each area. Results of such surveys indicated the 
location of probable chromite deposits. With these data as a basis, the northwestern 
section of the Webster area appeared to have the greatest concentration of chromite, and 
therefore was selected for core drilling. 

The purpose of the core drilling was to determine whether the magnetic anomalies 
found in the geophysical survey indicated the existence of underlying chromite bodies. In 
addition, it was hoped that the core drilling would aid in determining the extent of the con- 



PLATE 18 



O 




* 




D — 



C — 





7 00 



NOTES: 

Contours are isogams drawn at lOOand 500 

gamma intervals 

Observations were made with Askania Vertical 

Variometer 



Scale 10 

I M S B H-rt— 



20 Feet 



3 



CHROMITE SURVEY -DEMOCRAT, N. C. 



GEOPHYSICAL INVESTIGATION 
MAGNETIC MAP 



N C DEPARTMENT OF CONSERVATION S. DEVELOPMENT 
DIVISION OF MINERAL RESOURCES 

AND 

TENNESSEE VALLEY AUTHORITY 
COMMERCE DEPARTMENT 



KNOXVILLE 



1-2-42 | w lco! i 82IB5- 



PLATE 20 



o" 




■£» S 


_J ^ 






1 1 1 1 — 




5^ 


Q <C 




o cr 




=3 


3 U < 
^ O Ld 




S t& 




* * 


b_ ^ CC 




-£ 1 


UJ yj < 










1 •> 






i <£ 






H < £ 




=5 £ 


til Dl I 


is 


i-8 


"T" 

O jZ 

< 3 


O 


5^ 


2 O 






0) 








NJ 



Chromite Deposits of North Carolina 



27 



cealed ore bodies. At the time of this drilling, it was the intention of the Conservation 
Department and the Authority to drill other selected areas if the drilling at Webster 
proved successful. 

The locations of these core drill holes were so selected as to intersect points of likely 
occurrences of chromite as indicated by magnetic results or geological features. Six angle 
holes, totaling 738.8 feet, were drilled. (For location of holes see Plate No. 21). Re- 
ports 1 showing the coordinate layout used in the geophysical survey and the location of 
the core drill holes are on permanent file with the Commerce Department of the Tennessee 
Valley Authority at Knoxville, Tennessee, and the Division of Mineral Resources, North 
Carolina Department of Conservation and Development, Raleigh, North Carolina. 

PLATE 21 




CASING 110896 
wTbii GROyHp ip H07 56 „ 





Scale 



The drilling was done with a Sullivan drill, type 12, taking a core 2% inches in diam- 
eter. In Holes B, E, and F the core was reduced to li/s inches near the bottom because 
of unfavorable ground conditions. The core recovery was quite good considering the ex- 
tremely broken conditions of the dunite rock in which the drilling was done. The 
frequent occurrence of soft nickel silicate minerals, veins of chalcedony, and silica residue 



1. Murdock, T. G., "Horizontal Control — Webster and Democrat, N. C. Chromite Investigation," R. I. 24 
and 25, Division of Mineral Resources, North Carolina Department of Conservation and Development, 
Raleigh, N. C. "Location of Diamond Drill Holes, Webster, N. C. Chromite Investigation." 



28 Chromite Deposits of North Carolina 



made part of the drilling rather difficult. Since the chromite was found to occur in frac- 
ture zones, often filled with talc or weathered soft dunite, the core loss was rather high 
at the points where the chromite occurred. 

The results of the drilling were not very encouraging as the coring did not penetrate 
any outstanding chromite ore bodies. All the holes encountered one or more chromite 
zones but none of sufficient size to be of commercial importance under normal conditions. 
Holes B, D, and F, intersected narrow zones of vein chromite up to 21/2 feet thick. Hole D 
apparently intersected at a depth of 97 feet the same chromite vein-zone exposed in the 
overlying cut. In the cut the chromite zone is from 1 to 3!/2 feet thick. Assuming 
that this chromite vein-zone extends along the strike for 25 feet each way from the bot- 
tom of the cut or the drill hole and that the chromite is continuous from the cut to its 
point of intersection by the hole 90 feet below the cut, there is more than 600 tons of 
chromite at Hole D. Of the 738 feet drilled, about 165 feet contains approximately 21/2 
per cent disseminated chromite. 

All six holes intersected numerous nickel silicate mineral seams (genthite and 
garnierite) 1 composed of soft material difficult or impossible to core. Much of the core 
loss was due to these nickel silicate zones. Hole B intersected soft nickel silicate at a 
depth of 117 feet, which indicates the depth to which these secondary nickel minerals 
have been formed. In the upper 75-foot zone of all the holes nickeliferous seams occur 
every few feet which are identical with those exposed at the Olivine Products Company 
plant at Webster. The average of the analyses 2 of these nickel seams at Webster is 5.34 
per cent NiO. The drilling disclosed the existence of more nickel silicate mineral seams 
than were previously thought to exist in the area drilled. The possibilities of producing 
nickel along with chromite in the Webster area should not be overlooked. 

The drilling proved that the magnetic "trough lows" are mainly due to sound gran- 
ular olivine containing less than 5 per cent disseminated chromite. The broad circular 
magnetic "lows" were found to be due to clay pockets formed by deep weathering. The 
drill holes did not encounter as much chromite as is exposed in the surface cuts and pits. 
The drilling proved that the chromite bodies are mainly small disconnected lenses. 

Core drilling does not adequately explore chromite lenses of the type occurring in 
western North Carolina as these lenses are so small and discontinuous that there is much 
barren ground between them. Therefore, drill holes may miss the chromite lenses entirely 
as the barren area is likely to be greater than the area represented by the small chromite 
body. 

The following logs give a more detailed account of the core drilling. 



1. Eckel, E. C, and others, "Iron, Chromite and Nickel Resources of the Tennessee Valley Region," TVA 
Geologic Bulletin No. 10, p. 22, 1938. 

2. Pawel, G. W., "Nickel in North Carolina," Engineering and Mining Journal, October 1939, p. 35. 



Chromite Deposits of North Carolina 



29 



GENERALIZED LOGS 1 OF CORE DRILL HOLES, WEBSTER, JACKSON 
COUNTY, NORTH CAROLINA 



Location: H-10, S. 31° 41' 
Direction, North. 

in Feet 



Hole Number A 

W., 53.91 Feet; Surface Elevation 1093.48 2 Angle 45' 



Depth 
From 


13.8 

23.9 

27.8 

34.5 
44.7 



To 

13.8 
23.9 

27.8 
34.5 

44.7 

55.7 



Core 



55.7 
61.5 
71.7 


61.5 
71.7 
74.5 


74.5 
76.2 


76.2 

78.2 


78.2 
78.7 
80.0 


78.7 
80.0 
88.1 
88.1 


Location : 


H-10, 


Depth 

From 



5.1 
11.3 


±JLL CL 

in Feet 

To 

5.1 
11.3 
26.7 


26.7 
31.3 


31.3 
51.2 


51.2 
54.0 
55.5 


54.0 
55.5 
60.0 



60.0 
66.0 



66.0 



Clay (red). 

Weathered dunite containing about 2% disseminated chromite. 
loss about 25%. 

Relatively sound dunite, chalcedony and talc seams. Core loss 25%. 
Weathered dunite, talc veins containing chromite blebs and numerous 
small nickel silicate veins (genthite and garnierite). Core loss 10%. 
Relatively sound dunite containing small seams of nickel silicate min- 
erals. Core loss 10%. 

Very sound coarse-grained dunite containing about 2% disseminated 
chromite. 

Sound dunite containing small nickel silicate seams. 
Weathered and sound dunite containing talc and nickel silicate seams. 
Chalcedony and silica residue from leached olivine. Core loss 70%, 
probably mostly soft green nickel silicate minerals. 
Relatively sound dunite containing about 2% disseminated chromite. 
Broken fault zone filled with talc and white tough asbestos. Core loss 
25%. 

Very sound dunite. 

Fault zone filled with talc, actinolite, chlorite, and vermiculite. 
Relatively sound dunite containing talc and chalcedony seams. 
Bottom of hole. Hole filled at 40 feet by cave-in. 

Hole Number B 

W., 63.42 Feet; Surface Elevation 1096.05 Angle 83°; 



Red clay and weathered rock. 

Weathered dunite containing about 3% disseminated chromite. 
Highly weathered dunite and soft nickel silicate seams. Chromite 
cuttings. Core loss 90%. 

Weathered dunite containing about 2% disseminated chromite. 
Alternating weathered and sound dunite containing talc and nickel sili- 
cate veins. Estimated to contain about 3% chromite. 
Partly weathered dunite containing about 4% chromite. 
Weathered dunite and chalcedony. Core loss 95%. 
Weathered and sound dunite containing a little disseminated chromite 
and nickel silicate veins. 

Highly jointed and weathered dunite containing talc and nickel silicate 
veins. Fault at 63 in which there are */•> inch chromite crystals. 



in 



84.8 Sound and weathered dunite containing 2% disseminated chromite. 



Detailed logs are on file with the Division of Mineral Resources, North Carolina Department of Con- 
servation and Development, Raleigh, N. C, and the Regional Products Research Division of the Com- 
merce Department of the Tennessee Valley Authority, Knoxville, Tennessee. 
Datum for elevations is not sea-level but arbitrarily taken as 1,100 feet for Station H-ll on the grid. 



32 Chromite Deposits of North Carolina 



Hole Number F 

Location: H-10, N. 67° 33" W., 84.20 Feet; Surface Elevation 1107.56 Angle 66°; 
Direction, South. 
Depth in Feet 
From To * 

13.1 Weathered mica schist. 

13.1 14.3 Asbestos and talc. 

14.3 25.5 Talc, vermiculite, and soapstone. 

25.5 28.8 Laminated soapstone. 

28.8 33.9 Chlorite schist and talc. 

33.9 35.2 Chalcedony, talc, and silica residue from leached dunite. 

35.2 82.7 Talc, soapstone, chalcedony, and nickel silicate seams, 60% core re- 

covery. 
82.7 94.0 Highly weathered serpentinized dunite, talc, and nickel silicate seams. 

Serpentinized dunite appears to contain about 3% disseminated chro- 
mite. 
94.0 115.2 Highly fractured and steatitized dunite. Parts of zone contain about 

3% disseminated chromite. 

115.2 117.1 Talc zone impregnated with chromite crystals. Probably 25% chro- 

mite. 50% core loss. 

117.1 123.1 Highly weathered and steatitized dunite. Contains small amount of 

chromite. 

123.1 124.4 Highly laminated dunite. 

124.4 126.5 Weathered and broken talc and dunite containing both vein and dis- 

seminated chromite. 60% core recovered. Chromite content estimated 
at about 15%. (Note that this is probably the same chromite zone as 
that showing in shaft over hole) . 

126.5 135.9 Serpentinized and sound dunite, containing about 2% disseminated 

chromite. 
135.9 141.0 Broken dunite cemented with green talc, containing about 3% dis- 

seminated chromite. 
Chromite and talc. 50% core loss. 
Weathered dunite and talc. 
Chromite and talc. Water lost at 144.9. 
Weathered dunite. 20% core loss. 
Talc and chromite. 

Vermiculite, asbestos, talc, chlorite. 30% core loss. 
Sound green dunite containing about 2% disseminated chromite. 
Bottom of hole. 

MINING OF CHROMITE 

The mining of chromite from the North Carolina deposits has in the past presented 
certain difficulties, due principally to its occurrence in discontinuous, irregularly shaped, 
roughly lenticular bodies varying widely in size as well as shape. As previously stated, it 
may also occur disseminated as grains, arranged in bands of varying grade, in the dunite 
masses, and as crystals and fragments in soil overburden. 

PROBLEMS OF CHROMITE MINING 

The problems of chromite mining in general have been outlined by Nixon, 1 and while 
this exposition was with reference to the Oregon deposits it is in many respects quite ap- 



141.0 


143.1 


143.1 


144.3 


144.3 


144.9 


144.9 


150.0 


150.0 


151.7 


151.7 


157.2 


157.2 


162.7 




162.7 



1. Nixon, E. K., "Chromite — An Immediate National Need." Oregon Department of Geology and Mineral 
Resources. The Ore Bin. Vol. 4, No. 1 (Jan. 1942), p. 3. 



Chromite Deposits of North Carolina 33 



plicable to those in North Carolina. Briefly stated, once chromite is found in place, 
development work is required in order to indicate the extent and attitude of the occur- 
rence. This work usually means, first, surface cuts and trenches and, second, underground 
work in the form of shaft sinking and drifting. The amount of development required, 
will, of course, depend upon the size of the deposit. In the case of a small ore body, de- 
velopment work usually will extract all of the ore, and thus development and mining go 
hand in hand. Mining of small ore deposits is done by hand, since the quantity of ore 
available may not warrant purchase of power drilling equipment. For large proved de- 
posits, power equipment applicable for mining any lode deposit would be suitable. Speaking 
generally, however, power equipment should be kept at a minimum in advance of fairly 
accurate knowledge of the extent of the ore body. Small deposits usually require hand 
sorting as the ore is mined, in order that all waste be removed and only the best ore obtain- 
able retained for shipment. In mining larger deposits, hand sorting for removal of waste, 
insofar as practical, should be done. Concentration by milling equipment may be practical 
provided the proved extent of the deposit warrants the necessary capital expenditure and 
provided the ore is of such character that sufficiently high-grade grains of chromite may 
be mechanically separated from the gangue. In the case of chromite sands, a concentrating 
plant is essential and requires specialized operation. Such operations should not be under- 
taken except by technically qualified operators. In all cases where milling plants are con- 
templated, they should be designed by a qualified metallurgist and planned only after 
proper testing work is completed. Some low-grade chromites are not amenable to treat- 
ment mechanically so as to produce a satisfactory concentrate. 

Unit cost of mining (cost per ton) is an elastic figure, but is usually interpreted as 
including all costs incident to getting the ore to a surface stockpile or to the concentrator 
bins. Very little information on the cost of mining chromite in the United States is avail- 
able, since up to 1941 there was practically no domestic production. Costs will vary widely 
depending upon the size, type, and location of the deposit, and upon the experience of 
operators. This is true for any mineral deposit, but is especially applicable to discon- 
tinuous, lens-like ore bodies in the mining of which the proportion of dead work to total 
quantity of ore removed is high. In the cost of mining lode chromite, as in other lode 
deposits, the labor cost would be by far the largest single item and might amount to 70 or 
80 per cent of the total cost of extraction. Added to this would be the cost of explosives, 
sorting, power, timbering, supervision, assaying, and any dead work necessary in opening 
the deposit. Unit cost of mining small or medium-size deposits may be $6.00 or $7.00 and 
up per ton. The critical factors in lode chromite production are grade and size of deposit. 
together with transportation facilities. The critical factors governing operation of a 
chromite sand deposit are thickness of overburden, grade and extent of chromite sand. 
The importance of determininag the proper method of concentration has been mentioned 
above. 

placer Operations at democrat 

The only recently active chromite property in North Carolina is near Democrat just 
south of the Ivy River. Here the occurrence of chromite sand as crystals and fragments 
of chromite in the soil overburden capping, and derived from the weathering of the 
underlying dunite mass was of sufficient richness to permit its exploitation, even under 



34 Chromite Deposits of North Carolina 



existing economic conditions. Such an occurrence as a chromite sand offers no difficulties 
to modern placer mining methods ; in fact, an adjacent area was worked to a limited ex- 
tent during 1917-18. 

For several months during the summer and fall of 1941, the Southern, Minerals Com- 
pany of Asheville carried on operations at the property, first treating an old concentrate 
pile remaining from previous work. The equipment in use involved the minimum expendi- 
ture possible and also had the advantage of being readily portable, thus permitting its 
transfer to another area in the same district, to some other chromite property, or even 
to some other region to undertake the exploitation of another mineral which might offer 
greater possibilities of profit under changing economic conditions. 

Conditions are quite favorable for placer operation in that a sufficient amount of water 
is available in the Ivy River, the shape of the hill to the south is such that the sluiced 
material flows readily down to the feed sump, and the river permits ready disposal of the 
fine tailings. An unfavorable factor is the thinness of the chromite-bearing soil overburden 
as in many places sound bed rock of dunite is encountered within three feet of the surface. 
The thickness of the overburden increases to the south of the area being sluiced at the 
time of examination. 

The equipment for mining and concentrating consisted of two pumps mounted on 
rubber-tired trailers, for pumping into tanks supplying the jig and table, and for washing 
the chromite-bearing overburden down into the sluice ; a bucket elevator for feeding the 
jig with the sluiced material; a Pan-American two-compartment duplex jig of the bal- 
anced type; a James standard Wilfley table 4*/2 feet by 15 feet; and the necessary driving 
mechanism, pipe lines, tanks, hose, and sluice box. A trommel was later installed between 
the bucket elevator and jig to permit the removal of trommel screen oversize waste ma- 
terial without its having to pass the jig as was the original procedure. Plate 16 shows the 
location of the various plant units. 

The operating procedure may be briefly described as follows. The chromite-bearing 
soil was washed by a nozzle, water pressure being 75-100 pounds, and water consumption 
at least 500 gallons per minute. The washed material was thus sluiced by gravity into 
a wooden flume and thence to a dewatering pit adjacent to the concentrating unit, passing 
over a grizzly where large boulders, weeds, and trash were removed. From this pit a 
bucket elevator discharged the feed into the Pan-American jig. The jig consisted of two 
cells, the first of which had a 1/16 inch screen and the second a 3/16 inch one, and was 
operated at 100 pulsations a minute. The coarser concentrate from the jig went to concen- 
trate storage; the finer material to the table; and the jig tailings to the waste pile. The 
table made 250 to 300 vibrations per minute and produced three products : a concentrate 
to storage, a middling which was returned to the circuit, and a tailing to waste disposal. 
Water consumption of the jig and table amounted to 350 gallons per minute, under a con- 
stant head of 16 to 20 feet. Mechanical methods of transfer from jig to water were to 
be installed and also for disposal of coarser waste material. With these refinements it ap- 
peared possible to operate the plant with a four-man crew. The plant flow sheet is shown 
in Plate 22. 

The plant units were driven by gasoline motors: a 5-hp motor for the elevator, a 
3-hp one for the jig, and a lV-j-hp one for the table. 



Cr 


Fe 


Si 


P 


S 


37.99 


19.93 


0.80 


0.07 


Trace 


39.85 


19.32 


0.74 


0.07 


Trace 



Chromite Deposits of North Carolina 



Plant capacity was 100-150 tons of feed per eight-hour day, which could have been 
increased with some changes in the flow sheet. Chromite production amounted to 3 to 
4 tons of concentrate per day ; the product was around 48 to 50 per cent chromic oxide 
although a concentrate as high as 55 per cent could be obtained when desired. The fol- 
lowing is a chemical analysis 1 of the chromite produced and of a hand-picked concentrate 
of pure chromite from the product : 

Cr 2 0-, 

Table and Jig Concentrate 55.52 

Hand-Picked 58.24 

The occurrence of fine garnet in the overburden near the river indicated the possi- 
bility of its recovery as a by-product and some experiments were made upon such a 
procedure. 

Mining at this property was discontinued early in 1942, despite the fact that the 
operations had been well planned and conducted with new and adequate equipment. The 
exact reasons for the cessation of operations are not known, but the apparent failure of 
the enterprise is a further indication of the difficulty of successfully working North 
Carolina chromite. 

RECOVERY OF DISSEMINATED CHROMITE 

The possibility of the recovery of the chromite occurring as disseminated grains or 
crystals in the olivine and weathered dunite, an occurrence which is fairly common 
throughout the entire olivine belt, is one which should receive due consideration. Such a 
process would offer little technical difficulty and it could probably be effected with equip- 
ment such as that used at Democrat by the addition of the necessary coarse and fine grind- 
ing units. Likewise the mining of the ore-bearing material would be a simple quarrying 
operation and would present no greater problems than does the production of olivine for 
refractory use with a certain amount of selective mining. However, a considerable ton- 
nage of olivine would have to be processed to secure a ton of chromite, and the crushing 
and tailings disposal costs would be so high that the recovery would be of doubtful economy 
unless some market were found for the olivine. 

The mining and preliminary crushing of olivine could probably be carried out for 
$1.50, and allowing an additional $1.00 for finer grinding and additional processing would 
mean a total of $2.50 per ton of mill feed. If the value per ton of chromite concentrates 
is assumed to be $40.50, the base price offered by Metals Reserve Company for "High 
Grade" chrome ores containing 45.0 per cent Cr 2 3 and with a ratio of chrome (Cr) to 
iron (Fe) of 2.5 to 1, only 16.2 tons of feed could be milled at this price. This in turn 
would require a mill feed of 6.17 per cent chromite in the olivine, an average grade which 
appears difficult of achievement on a large scale. This example would also necessitate per- 
fect mill recovery, even if the requirements of the market were met and production cost 
including overhead and amortization was not more than $2.50. A greater chromite con- 
tent would be necessary to provide any profit to the operator. 



1. Chemical Analysis by J. W. H. Aldred, TVA Research and Development Division, Wilson Dam, 
Alabama. 



36 



Chromite Deposits of North Carolina 



The wider use and greater demand for olivine, however, will change the picture en- 
tirely. Any large scale development of the olivine deposits, particularly those known to be 
associated with the chromite occurrences described in preceding pages, such as to provide 
a raw material for the manufacture of magnesium salts or metal, may be expected to yield 
considerable by-product chromite at a low cost, both as pockets and lenses of massive 
chromite from mining and as disseminated chromite recovered from the residue and solu- 
tion after the olivine has been processed for its magnesium content. In fact this is the 
future of the North Carolina chromite deposits. 

PLATE 22 




■ Ovtrburden 
(day <f grave/) 



Olivine (bed rock) 






Chromite Deposits of North Carolina 



37 



PLATE 23 




Figure A. Small Chromite Vein 




Figure B. Small Chromite Lens in Dunite 



38 



Chromite Deposits of North Carolina 



PLATE 24 





i i 



Figure A. Field Magnetometer Party in Action 




Figure B. Core Drilling for Chromite, Webster, N. C. 



Chromite Deposits of North Carolina 



3£ 



PLATE 25 




Figure A. Hydraulicking Placer Chromite, Democrat, N. C 




Figure B. Portable Plant Recovering Placer Chromite, Democrat, N. C. 



:4'64 SI